Approval ' N
of certification
A Guide to the
Emissions
Certification
Procedures
Mileage accumulation
and emissions testing
for Alternative Fuel
Aftermarket Conversions
f ' Can any N^
unscheduled
maintenance be
justified? '
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A Guide to the
Emissions Certification Procedures
for Alternative Fuel Aftermarket Conversions
January 1998
U.S. Department of Energy (DOE)
U.S. Environmental Protection Agency (EPA)
Prepared by the National Renewable Energy Laboratory,
a U.S. DOE national laboratory
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<^ji^> Emission Certification Procedures
Preface
In February 1997, the U.S. Environmental Protection Agency (EPA) hosted a
public meeting in Washington, DC, to discuss its concerns about the ability of
aftermarket vehicle conversions to satisfy federal emissions standards. Those
concerns had been heightened by the recent publication of data indicating that
vehicles may exhibit increases in one or more regulated pollutants after their
fuel systems are converted from a conventional fuel to an alternative fuel.
As a direct result of the meeting, the U.S. Department of Energy (DOE)
offered to fund the development of a simple and straightforward reference
guide designed to explain the processes of emissions certification for aftermar-
ket conversions. DOE's offer was extended to satisfy stakeholders' requests for
more succinct explanations of the certification requirements of various regula-
tory agencies. DOE's National Renewable Energy Laboratory (NREL) was
assigned the task of collecting the information and publishing the guide.
Since the meeting in February, the EPA has made two important announce-
ments that relate to the certification of aftermarket vehicle conversions. The
first occurred on September 4, 1997, when the EPA issued an addendum to
Mobile Source Enforcement Memorandum 1 A. This document provides clarifi-
cations and revisions of the agency's tampering enforcement policy for alterna-
tive fuel aftermarket conversions. The second came on October 31, 1997
(just before this guide was published) in which EPA proposed changes to the
certification procedures designed to ease the burden of certification for vehicle
manufacturers who qualify for the Clean-Fuel Vehicle Program. Details from
both announcements are covered in this guide.
The guide contains extensive information provided by the EPA, the
California Air Resources Board (CARD), and the Colorado Department of
Public Health and Environment, as well as numerous fleet managers, coopera-
tive industry organizations, and equipment manufacturers, installers, and
distributors. NREL and DOE gratefully acknowledge the contributions of each
project participant.
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Emission Certification Procedures <\^V>
Table of Contents
Introduction 1
How to Use This Guide 1
What Is an Aftermarket Conversion? 3
A Historical Perspective 3
Authority for Emissions Certification 4
Certification by the U.S. Environmental Protection Agency 5
General Information 5
Regulations 5
Memorandum 1A and Addendum to Memorandum 1A 7
What Does Certification Apply To? 8
Overview of the Certification Process 10
Submitting an Application 10
EPA Review and Issuance of a Certificate of Conformity 12
Emissions Testing 18
On-Board Diagnostics (OBD) 22
Labels, Decals, and Maintenance Schedule 23
Record Keeping 24
Warranty 24
Audit and In-Use Surveillance 25
Responsibilities of Distributors and Installers 25
Clean-Fuel Vehicles and Mobile Emissions Reduction Credits 26
Certification by the California Air Resources Board 27
General Information 27
Regulations 28
What Does Certification Apply To? 28
Introduction to the Certification Process 29
Certification Plan, Application, and Fees 29
Emissions Standards 29
Emissions Testing 31
On-Board Diagnostics (OBD) Requirements 34
General Emissions Warranty Coverage 34
Owner's Manual, Maintenance Schedule, and Vehicle Labels 34
Record Keeping 34
Audit, In-Use Surveillance, and Liabilities 35
Responsibilities of the Installer 35
Penalties and Liabilities 35
Mobile Source Emission Reduction Credits 35
Frequently Asked Questions 37
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iv> Emission Certification Procedures
Appendices 41
Appendix A: Glossary of Terms (Abbreviations and Definitions) 41
Appendix B: Schematics of Commercial Aftermarket Conversion Systems 46
Appendix C: Informative Web Sites 48
Appendix D: Emissions Standards 49
Appendix E: Fuel Specifications for Emissions Certification Purposes 53
Appendix F: California Certification Process for Aftermarket Conversions-
Use of Gasoline Deterioration Factors 54
Appendix G: California Certification Process for Aftermarket Conversions—
Using Carry-Over and Carry-Across of Deterioration Factors 55
Appendix H: California Certification Process for Light- and Medium-Duty Aftermarket Conversions—
Using Derived Deterioration Factors 56
Appendix I: California Certification Process for Heavy-Duty Aftermarket Conversions—
Using Derived Deterioration Factors 57
Appendix J: Contacts 58
Appendix K: Important Documents 59
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Emission Certification Procedures
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viT> Emission Certification Procedures
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Photo Courtesy of Natural Fuels Corporation/PIX 05137
Introduction
Emissions certification is still relatively new to the aftermarket vehicle
conversion industry. Many in the industry think that as soon as a
vehicle is converted to operate on compressed natural gas (CNG) or
liquefied petroleum gas (LPG), it automatically runs as clean as or clean-
er than it did on the conventional fuel. However, recent studies have
shown that aftermarket conversions may not always reduce emissions.
To achieve emissions benefits, the conversion equipment must be
designed and calibrated specifically for the engine and emissions control
system on which it has been installed, and the installation and setup must
be performed so as to not adversely affect the vehicle's original emissions
performance. The reason for certification, then, is to ensure that these cri-
teria are met, that the vehicle continues to perform properly, and that it
continues to satisfy all appropriate emissions standards throughout its
useful life.
Technician performing a
quality assurance inspection of an
aftermarket conversion installation
How to Use This Guide
We have prepared this guide to help
equipment manufacturers, distributors,
and installers understand the emissions
certification process for aftermarket con-
versions. First and foremost, the guide
gives an overview of the certification
requirements established by the U.S.
Environmental Protection Agency (EPA)
and the state of California. It includes
information about the regulations that
apply to certification, identifies key steps
in the certification process, provides con-
tacts and reference sources for additional
information, and includes summaries of
emissions standards.
The material presented here relates to
dedicated and dual-fuel conversion types
designed to operate on CNG, liquefied nat-
ural gas (LNG), or LPG fuels. It applies to
light-duty vehicles and trucks, medium-
and heavy-duty vehicles (California only),
and heavy-duty engines. The test proce-
dures and regulations for certifying LNG
are identical to those for CNG. Therefore,
to minimize repetition of the terms CNG
and LNG, we use CNG only, although
either term or both terms could be used.
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Introduction
Some Words about Terminology
Appendix A is an extensive glossary of terms. However, a few
terms require early clarification.
1. Aftermarket conversion—a vehicle or engine originally
designed and certified to operate on gasoline or dieselthat
has been modified to run on an alternative fuel. Retrofit
kit or system, aftermarket conversion, and conversion
all have the same meaning, but for the sake of consistency,
we use "aftermarket conversion" throughout this guide.
2. Dual-fuel—we use the term "dual-fuel" to refer to vehicles
or engines that have two separate fuel systems and are
designed to run on either an alternative fuel or conven-
tional gasoline, but using only one fuel at a time. This is
consistent with the usage of the term in EPA and California
regulations.
3. Manufacturer—in the context of this guide, "manufac-
turer" refers to any company that produces, assembles, or
packages aftermarket vehicle conversion kits.
4. Emissions standards, procedures, and regulations—the
regulations governing aftermarket conversions also include
references to emissions standards and acceptable testing
and implementation procedures. Procedures are the meth-
ods that a manufacturer uses to test vehicles, systems, or
components. A standard is a regulated emissions level.
Examples of emissions standards are tier 1, transitional
low-emission vehicle (TLEV), and low-emission vehicle
(LEV). The sidebar on page 17 provides more information
about these standards.
5. Vehicle and engine—We use the terms "vehicle" and
"engine" frequently in the guide. In some parts of the cer-
tification process, different regulations or procedures apply
depending on whether you are certifying a vehicle or an
engine. In others, the regulations and procedures are iden-
tical for engines and vehicles. When there are no differ-
ences, we use the term "vehicle" frequently in this guide to
imply all vehicles and engines. This helps to avoid repeat-
ing "vehicle and/or engine" throughout. Unless otherwise
specified, the term "engine" is used to refer to heavy-duty
engines. Other specific terms used in the guide and the
regulations include light-duty vehicle, light-duty truck,
medium-duty vehicle, and heavy-duty vehicle. These terms
are defined in the glossary.
Emission Certification Procedures
Because EPA and California certifica-
tion processes differ, we have devoted a
separate section of the guide to each. In
each section, we have attempted to lead
you through all the major steps in the
emissions certification process.
First, we provide contact information for
each agency. Then, we present an overview
of the governing regulations, with specific
references to the necessary documentation.
We explain the certification process (with a
flow chart for visual reference), provide
examples, and define important terms.
Emissions standards and test procedures
are outlined and accompanied by refer-
ences to the appropriate sections of the
regulations. Finally, we describe other
responsibilities and requirements (such as
information labels, warranty requirements,
and record keeping) needed to obtain an
emissions certification.
The two sections in the back of the guide
provide answers to "Frequently Asked
Questions" and detailed reference material
in the form of appendices. The appendices
include a glossary of terms, sample
schematic diagrams, informative World
Wide Web sites, emissions standards, fuel
specifications, additional flow charts, and
an index of related documents.
The guide is not meant to replace the
use of EPA and California regulations; it is
designed to give an overview and to serve
as a reference. The official regulations are
the cornerstone for emissions certifica-
tion—they explain the detailed test proce-
dures and the emissions standards. Any
discrepancy between this guide and the
regulations is unintentional. Because both
EPA and California regulations are con-
stantly being updated, consult with the
EPA and the California Air Resources
Board (CARB) to ensure that you have
current information. If you're interested in
certifying vehicles, always refer to the
actual regulations governing the vehicles
or engines you wish to convert.
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Emission Certification Procedures
What Is an Aftermarket
Conversion?
An aftermarket conversion is a vehicle
that was originally designed, produced,
and certified by an original equipment
manufacturer (OEM) to operate on a par-
ticular fuel and has been altered to allow it
to operate on a different fuel. Typically, an
aftermarket conversion involves modify-
ing a gasoline- or diesel-fueled vehicle to
run on CNG or LPG. After conversion, the
vehicle may be "dedicated" to an alterna-
tive fuel, meaning that it can operate solely
on the new fuel, or it can be "dual-fuel,"
meaning that it can run either on the con-
ventional fuel or the alternative fuel, but
not on both simultaneously. In the context
of this guide, dual-fuel vehicles produced
under the qualified vehicle modifier pro-
grams of various OEMs are not consid-
ered to be aftermarket conversions.
Aftermarket conversion of vehicles
involves removing, altering, or replacing
various fuel system components. The con-
version equipment is frequently called a
"conversion kit." Many companies pro-
duce conversion kits, and each kit has its
own unique characteristics. Schematics of
two such kits, which are commercially
available today, are contained in Appen-
dix B.
A Historical Perspective
Emissions control regulations date back
to the early and mid-1960s. California
required its first emissions control systems
on 1966 vehicles. In 1967, GARB was estab-
lished to ensure the protection of air qual-
ity, including motor vehicle emissions.
In 1970, the federal Clean Air Act (CAA)
was adopted and the EPA was created.
The CAA gave the EPA broad responsibili-
ties for regulating motor vehicle pollution.
Emissions standards for crankcase, ex-
haust, and evaporative emissions from
light-duty vehicles, as well as standards
for exhaust emissions from heavy-duty
gasoline- and diesel-fueled engines,
became effective during that same year.
In 1974, the EPA issued an important
policy statement known as Memorandum
1A ("Interim Tampering Enforcement
Policy," see page 7), which outlined steps
that aftermarket conversion companies
could take to ensure that installing their
kits and equipment did not violate the
CAA's anti-tampering provisions. One
such method was to obtain a representa-
tion from a state environmental control
agency that the converted vehicle's emis-
sions performance had not been compro-
mised. For instance, through its Regulation
No. 14 ("The Control of Emissions from
Alternative Fueled Motor Vehicles"), the
Colorado Department of Health and
Environment provided a process for
obtaining a "Letter of Certification" for
vehicles converted in Colorado.
California has had the longest-running
certification program for aftermarket con-
versions, establishing its first regulations
in 1975. Since then, California has updat-
ed its certification procedures for after-
market conversions a number of times.
In 1994, the EPA established the first
national emissions standards and regula-
tions for vehicles and engines powered by
CNG and LPG (see 59 Federal Register [FR]
48472). These standards and regulations
apply to aftermarket conversions and vehi-
cles produced by OEMs. The certification
process outlined in the EPA's rule-making
was optional prior to the 1997 vehicle
model year, but it is required for 1997 and
successive model years. Prior to 1994, no
federal emissions standards or test proce-
dures existed for CNG and LPG vehicles.
On September 4,1997, the EPA revised
and updated the tampering enforcement
policy with an addendum to Mobile
Source Enforcement Memorandum 1A
("Tampering Enforcement Policy for
Alternative Fuel Aftermarket Conver-
sions"). As outlined in the addendum,
the EPA no longer accepts Colorado
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Introduction
Regulation No. 14 or the California certifi-
cation procedure for 1993 and earlier
model year vehicles as an adequate
demonstration that a vehicle or engine
modified with an aftermarket conversion
system complies with the applicable emis-
sion standards for its useful life. The
addendum outlines three alternatives for
providing a reasonable basis that an after-
market conversion does not adversely
affect emissions performance. The EPA
section of this guide presents additional
information on the addendum.
Authority for Emissions
Certification
Section 209 of the CAA provides that
"no state or political subdivision thereof
shall adopt or attempt to enforce any stan-
dard relating to the control of emissions
from new motor vehicles or new motor
vehicle engines subject to this part."
However, this requirement is •waived for
states that adopted emissions control
standards prior to March 30, 1966. Based
on this waiver, the state of California may
adopt and enforce its own emissions
standards.
Emission Certification Procedures
In all cases, manufacturers of new
motor vehicles and engines must receive
certification from the EPA before the vehi-
cles can be introduced into commerce.
For California-only vehicles, the manu-
facturer first obtains certification from
CARB, then submits this to the EPA for
certification. The EPA will then issue a
California-only certificate. For all other
new vehicles, manufacturers must first
obtain a certificate from the EPA. This also
applies to aftermarket conversions, except
for vehicles converted according to the
steps outlined in the addendum to Mobile
Source Enforcement Memorandum 1A.
Currently, manufacturers may obtain
emissions certification for aftermarket
conversions from the EPA and the state of
California. For more information on this
subject, see the sections of this guide on
EPA and California certification, along
with the section entitled Frequently
Asked Questions.
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Emission Certification Procedures
Certification by the
U.S. Environmental Protection Agency
General Information
The EPA is responsible for federal emis-
sions certification of motor vehicles and
motor vehicle engines in the United
States. As we noted in the introduction,
California may also grant emissions
certification to vehicles and engines for
use in California.
Regulations
The U.S. regulations regarding air
quality are contained within Title 40
("Protection of Environment") of the Code
of Federal Regulations (CFR). Title 40 com-
prises 18 volumes, and each volume is
separated into parts for ease of reference.
Title 40 is updated each July with any new
regulations enacted during the previous 12
months, including changes and additions
as recorded in the Federal Register (FR).
The regulations governing emissions
certification and test procedures are con-
tained within Part 86 ("Control of Air
Pollution from New and In-Use Motor
Vehicles and New and In-Use Motor
Vehicle Engines: Certification and Test
Procedures"), and the final rules for Part
86 as listed in the FR. This material applies
to OEM vehicles, to OEM heavy-duty
engines, and to aftermarket conversions.
Who to Contact
EPA Light-Duty Vehicles and Trucks
Environmental Protection Agency
Office of Mobile Sources
Vehicle Programs and Compliance Division
Vehicle Programs Group
2565 Plymouth Road
Ann Arbor, MI 48105
EPA Alternative Fuels Hotline
Telephone: (734) 668-4312
Fax: (734) 741-7869
**New Hotline numbers as of May 1998
Telephone: (734) 214-4312
Fax: (734) 214-4869
EPA Heavy-Duty Engines
Environmental Protection Agency
Office of Mobile Sources
Engine Compliance Programs Group
Mailing Address:
401 M St. S.W. (6403J)
Washington, DC 20460
Visiting Location and Courier Shipments
501 3rd St. N.W.
Washington, DC 20001
Telephone: (202) 564-9261
Fax: (202) 565-2057
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Emission Certification Procedures
Table 1
The Parts of Title 40 of the Code of Federal Regulations (CFR) That Affect
Certification of Aftermarket Conversions
Part
85
86
88
600
Name
Control of Air Pollution from Motor Vehicles and Motor Vehicle Engines
Control of Air Pollution from New and In-Use Motor Vehicles and
New and In-Use Motor Vehicle Engines: Certification and Test Procedures
Clean-Fuel Vehicles
Fuel Economy of Motor Vehicles
The FR is an important reference
source. It is the official publication for
Notices, Rules, and Proposed Rules from
federal agencies and organizations. As
part of the regulation and rule-making
process, the FR contains a preamble for
the regulations. This preamble provides
manufacturers "with information that
addresses many frequently asked ques-
tions about the regulations.
Table 1 lists the other parts of Title 40
that are key to the certification process.
For example, Part 85 (or 40 CFR Part 85, as
it is more technically known) contains the
provisions under which parties are
exempt from the tampering prohibition
contained in Section 203 of the CAA (see
the sidebar on page 7). Also, Part 88
contains the regulations that govern the
Clean-Fuel Vehicle (CFV) and the Clean-
Fuel Fleet (CFF) Program requirements.
Because the EPA updates its require-
ments from time to time, information
presented here about the location of
certain rules and regulations is also subject
to change. To obtain the most up-to-date
information, check with the EPA.
On October 31, 1997, just before this
guide was printed, the EPA issued a draft
of a number of proposed changes to 40
CFR Part 86. The changes ease the burden
of certification for manufacturers of CFVs.
The title of the proposed rule is
Expanded Engine Family Definition, Fee
Exemption, and Revised Definition for
Dedicated Fuel System for Vehicles and
Engines Meeting Low-Emission Vehicle
(LEV), Inherently Low-Emission Vehicle
(ILEV), Ultra-Low Emission Vehicle, or
Zero Emission Vehicle Exhaust Emission
Standards. It is available from the EPA
Office of Mobile Sources Clean Fuel Fleets
World Wide Web site, listed in Appendix C.
In this document, the EPA has pro-
posed revisions to the definition of dedi-
cated fuel systems, adopted provisions to
allow manufacturers of CFVs to group
certain engine families into engine family
classes, and provided for an exemption
from certification fees for vehicles meet-
ing CFV emissions standards. The revised
definition of a dedicated vehicle includes
vehicles capable of operating on a second
(conventional) fuel for a maximum of one
hour in any three-hour period, or with a
total conventional fuel capacity that
allows for an operational range of 50
miles. The proposed rule allows engine
families to be grouped under engine fami-
ly classes as defined in the document. The
proposed fee ex-emption would be avail-
able for vehicles that certify to the EPA's
LEV, ultra low-emission vehicle (ULEV),
inherently low-emission vehicle (ILEV),
or zero-emission vehicle (ZEV) emissions
standards.
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Emission Certification Procedures
Memorandum 1A and
Addendum to Memorandum 1A
As noted in the introduction, in 1974
the EPA clarified the tampering prohibi-
tion contained in Section 203 of the CAA.
Memorandum 1A, or Memo 1A as it is
commonly known, states, in part, that
using an aftermarket part, alteration, or
add-on part will not constitute tampering
if the manufacturer has a reasonable basis
to believe that such alterations will not
adversely affect emissions performance.
Through Memo 1A, the EPA outlined
steps for aftermarket conversion compa-
nies to follow to arrive at this reasonable
basis. The two main methods were:
(1) perform emissions testing after instal-
lation, following all federal procedures to
ensure that emissions were within the
standards for the model year in question
over the useful life of the vehicle; or
(2) have a federal, state, or local environ-
mental control agency accept that the
converted vehicle's emissions perfor-
mance has not been compromised. This
latter provision was limited to the
geographic area over which the state or
local government had jurisdiction.
In an important update on September 4,
1997, the EPA released an addendum to
Memo 1A, which clarifies the tampering
enforcement policy and revises the terms
for establishing the reasonable basis. The
revised policy states "EPA will no longer
accept a representation based on the
pre-1994 California Procedures for alter-
native fuel conversion systems or on the
procedures under Colorado Regulation
No. 14." Three options are listed for estab-
lishing a reasonable basis:
1) A federal Certificate of Conformity
under 40 CFR Part 86 or 40 CFR Part 88
2) A retrofit system certification (Exe-
cutive Order) from CARB under
the "California Certification and Instal-
lation Procedures for Alternative Fuel
Retrofit Systems for Motor Vehicles
Certified for 1994 and Subsequent
Anti-Tampering Provision of the Clean Air Act
(Section 203 (a) (3))
"The following acts and the causing thereof are
prohibited . . .
(3) for any person to remove or render inoperative any device
or element of design installed on or in a motor vehicle or
motor vehicle engine in compliance with regulations under
this title prior to its sale and delivery to the ultimate pur-
chaser, or for any person knowingly to remove or render inop-
erative any such device or element of design after such sale
and delivery to the ultimate purchaser."
Model Years and for All Model Year
Motor Vehicle Retrofit Systems Certified
for Emission Reduction Credit" for a
conversion system installed and tested
under the above procedures on a vehi-
cle or engine from a 50-state engine
family for use nationwide, or for a con-
version system installed and tested
under the above procedures on a vehi-
cle or engine from a California engine
family for use in California only
3) Until December 31, 1998, the use of an
alternative fuel conversion system
designed, tested, and installed on a
single engine family, or multiple engine
families (providing certain conditions
are met) if testing is complete by March
31,1998.
The addendum details the conditions
required by Option 3. In general terms,
Option 3 allows, for a limited time, manu-
facturers to establish a reasonable basis by
performing specific emissions testing and
demonstrating that the test vehicle or
engine conforms with emissions standards
after conversion.
Copies of the EPA policy are available
from the EPA's Mobile Source Enforce-
ment Branch at 202-564-2255 or on the EPA
Office of Mobile Sources Web site. Refer to
Appendix C (Informative Web Sites) and
Appendix J (Contacts) in this guide for
addresses.
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Emission Certification Procedures
An Example of Determining the Duration of a
Certificate of Conformity
In the following example, the term "model year" refers to the
model year of the certified aftermarket conversion, not the
vehicle's original model year. EPA Certificates of Conformity
are good for one model year, which must always include
January 1 of the calendar year for which it is designated and
may not include January I of any other calendar year. The
maximum duration of a model year is one calendar year plus
364 days. The certificate has an effective date on which con-
versions may begin, and they must stop no later than
December 31 of the model year. If your company were issued
a 1998 model year certificate with an effective date of
September 26, 1997, you could start conversions on the
effective date and convert vehicles through to December 31,
1998.
To take advantage of the maximum period for converting
vehicles, your company would try to have the certificate
issued with an effective date of January 2 of the year prior to
the model year. For example, a 1998 model year certificate
could be issued with an effective date of January 2, 1997, so
that conversions could be done from January 2, 1997 through
to December 31 of 1998 (one calendar year plus 364 days).
What Does Certification Apply To?
The EPA certification procedures give
manufacturers a method to follow for cer-
tifying light-duty vehicles and trucks, as
well as heavy-duty engines, to operate on
CNG or LPG, either in dedicated or dual-
fuel modes. Manufacturers that success-
fully complete the process receive a
"Certificate of Conformity" from the EPA.
With this certificate, manufacturers may
convert the engine family or vehicle refer-
enced in the certificate. Further, they
become exempt from the tampering pro-
visions under the CAA for the duration
specified, as long as the vehicles are
converted in the exact manner in which
they were certified.
Each Certificate of Conformity applies
to a specific engine family (see sidebar on
page 9). The manufacturer or installer
may only convert vehicles in the engine
family named on the certificate. The cer-
tificate is valid for a single model year,
and it lists the period during which vehi-
cles from the specified engine family may
be converted. The sidebar on this page
contains an example of how these dates
are established and applied.
There are three basic federal emissions
certifications: (1) the so-called "49-state"
certification, under which vehicles can be
certified for operations in all states except
California; (2) "50-state" certification,
under which vehicles can be certified for
operations throughout the country (vehi-
cles issued a "50-state" certification and
scheduled to be operated in California
must also be certified by CARB); and
(3) "California-only" certification, under
which vehicles can be certified for opera-
tion in California only. California-only
vehicles must first go through the CARB
certification. This provision applies to
OEM vehicles and to aftermarket conver-
sions.
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Emission Certification Procedures
Engine Family Names Explained
For the purposes of emissions certification, and for ease in identification, the EPA classifies vehicles and
engines with a standardized 12-character code known as an engine family name. Engines are grouped
into families based on criteria provided in 40 CFR Part 86 (see 86.096-24), and the EPA's Advisory
Circular No. 20-B, dated June 27,1974 ("Determination of Engine Families and Classification of Emission
Control Systems"). Changes in the format are scheduled to take effect for the 1998 model year. Although
briefly outlined below, more information on the changes is available on the EPA's Office of Mobile
Sources' World Wide Web site (see Appendix C, Informative Web Sites, for EPA Standardized Engine and
Evaporative Family Names).
1997 and Earlier Model Years
The engine family name contains a wealth of information about a given vehicle or engine, including:
• The vehicle or engine model year
• Manufacturer
• Engine displacement
• Vehicle or engine class (for example, light-duty vehicle or heavy-duty engine)
• Fuel system (such as valves per cylinder, carburetor, or fuel injection)
• Combustion cycle (such as Otto or diesel) and fuel
• Applicable emissions standards
• Exhaust gas aftertreatment device (for example, a catalyst or a particulate trap)
• Whether on-board diagnostics (OBD) regulations apply.
VFM4.628GKEK is an example of a 1997 engine family code for a 1997 (V); Ford Motor Company (FM);
4.6 liter engine (4.6); in a light light-duty truck with a loaded vehicle weight between 3,751 and 5,750
pounds (2); equipped with electronic multi-point fuel injection and two valves per cylinder (8). It is an
Otto-Cycle piston gasoline engine (G); certified to tier 1 emissions standards (K); with a three-way cat-
alyst (E); and complies with federal OBD or California OBD II requirements (K).
Beginning with the 1998 Model Year...
The engine family name format has changed, although it still contains 12 characters. The first character
is the model year, the second through fourth are the code for the manufacturer, the fifth is the family
type (for example, light-duty vehicle, light-duty truck, heavy-duty engine), the sixth through ninth are
displacement in liters, and the tenth through twelfth are reserved for the manufacturer's own use.
WG9XT05.46BF is an example of a 1998 engine family code—the W signifies 1998 model year; the G9X
signifies GFI Control Systems, Inc.; the T signifies light-duty truck family; the 05.4 signifies 5.4 liters;
and the 6BF is a code defined by the manufacturer. Much of the information contained in the 1997 and
earlier engine family names for light-duty vehicles and trucks is now included in the vehicle emission
configuration bar code label (or format), which is part of the emissions control information label.
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Emission Certification Procedures
Small Volume Manufacturer Status and Its Benefits
A small volume manufacturer is defined as a company that will
sell or convert fewer than 10,000 vehicles or engines during
the model year in question. The company must apply to the
EPA for this status. If the company qualifies under the speci-
fic terms that the EPA outlines, options for developing DFs
may prove beneficial (see the discussion beginning on page
20 for more information about DFs).
A small volume manufacturer may qualify for a partial waiver
of the certification fees, and may also qualify for a delay in
the initial years of the phase-in schedules for certain emis-
sions regulations. Refer to 40 CFR Part 86.085-l(e) for the cri-
teria used to qualify companies as small volume manufacturers
and to 40 CFR Part 86.098-14 for the 1998 model year certifi-
cation procedures applicable to small volume manufacturers.
Overview of the Certification
Process
Figure 1 illustrates the steps necessary
for obtaining EPA certification. The
process outlined here applies to small
volume manufacturers of aftermarket
conversions (the sidebar on this page
explains small volume manufacturer sta-
tus). The process includes applying to
EPA for small volume manufacturer sta-
tus, paying fees, conducting durability
and emissions testing, comparing the test
results with applicable emissions stan-
dards, applying for certification, and
obtaining the Certificate of Conformity.
The EPA furnishes an information pack-
age to companies interested in certification
using the small volume manufacturer
rules. The information package contains
reference materials about the certification
process, the criteria companies must use to
qualify as small volume manufacturers,
instructions on applying for small volume
manufacturer status, and other details such
as the application fees.
After receiving the EPA information
package, each company must decide
whether it is interested, and determine
whether it qualifies for small volume
manufacturer status. If the answer to both
questions is "yes," the next step is to send
a written request for the status to the EPA.
The written request must include respons-
es to the list of questions contained in the
information package. If the request is
granted, the EPA will issue a manufactur-
er 's identification code. Next, the compa-
ny must submit the application fees (see
the section on page 13 entitled "Fees,"
along with Table 2 on page 12).
The company must then determine the
process it wants to use to establish deterio-
ration factors (DFs). DFs are used to
predict the increase in vehicle emissions
associated with increased mileage accu-
mulation (see the example contained in the
discussion and sidebar on page 20).
After establishing the process for deter-
mining DFs, emissions testing can begin
(see 40 CFR Part 86.094-14(c)). For light-
duty vehicles and trucks, the EPA may
decide to undertake additional testing of
its own to verify emissions results. The
manufacturer may be required to provide
a prepared vehicle to the EPA for this test-
ing. More information about emissions
testing is provided in the section of this
guide beginning on page 18. Once all the
test results are gathered, the company
submits an application for certification to
the EPA for its review.
Submitting an Application
Submitting an application is really the
final step in the process of obtaining emis-
sions certification of a vehicle from the
EPA. The application represents the
culmination of considerable information
gathering, and formally presents that
information in such a way as to facilitate
the EPA's review and acceptance. To
shorten the review process and to guaran-
tee the speediest response time, the EPA
suggests submitting the application in the
format outlined in its information pack-
age. Following the EPA's directions and
providing the exact information requested
will result in the quickest turnaround.
-------
Emission Certification Procedures
Contact EPA for information package
Apply to EPA for small volume manufacturer status
Is this a
California-only engine
family with EO?
Yes
Conduct partial durability
testing. For dual-fuel
vehicles,* test on both fuels
Conduct full durability
testing. For dual-fuel
vehicles,* test on both fuels
Figure 1:
Federal Certification Process
for Aftermarket Conversions
to Be Used by Small Volume
Manufacturers
Use EPA-assigned or
manufacturer-established DFs
Select and test emission data vehicle.*
For dual-fuel vehicles, test on both fuels. Apply DFs
Determine compliance with standards
No
O
Manufacturer
Action
EPA
Action
Abbreviations
DF Deterioration Factor
EPA Environmental
Protection Agency
EO Executive Order from CARB
In this figure, the term
"vehicle" collectively refers
to light-duty vehicles and
trucks, and heavy-duty engines
Prepare test vehicle and send it to EPA
\
EPA performs verification tests
Prepare required data; submit an application for certification to EPA
\
EPA issues a Certificate of Conformity
T
Keep EPA informed by updating the
application whenever design changes are made
-------
Emission Certification Procedures
Table 2
EPA Certification Fees
Vehicle or Engine Type
Light-Duty Vehicle
or Truck
Heavy-Duty Vehicle
or Engine
Certification Type
Federal
California Only
Federal
California Only
Fee Per Certification
$23,731
$9,127
$12,584
$2,145
For light-duty vehicles and trucks, the
information that must be submitted with
the application package includes:
• Pertinent company information, along
with the name of the contact person
• A brief description of the vehicles to be
certified, including:
Engine family name and vehicle
models
List of parts to be added, removed,
and modified
Conversion equipment description
Engine details
Emissions control system details
Engine calibration information -
Durability information
• All emissions test results, and informa-
tion about the facility that performed
the tests
• Emissions standards with which the
vehicle complies
• Appropriate signatures ensuring that
the regulations have been met
• Examples of the emissions control
labels, as well as examples of the ILEV
decals if the certification is to meet
ILEV standards (see the discussion on
page 23 of this guide)
• Maintenance instructions
• Emissions warranty statements (see the
discussion on page 24 of this guide)
• Statement of compliance.
To certify vehicles to the CFF Program
(see 40 CFR Part 88), the application must
also include the name of the installer(s)
who will complete the conversions if the
installer(s) is different from the holder of
the certificate.
The application for heavy-duty engines
is similar, but is currently under review
as a result of an effort to reduce the level
of reporting. Contact the EPA Office of
Mobile Sources, Engine Compliance
Programs, listed in Appendix J, and ask for
the U.S. EPA Large Engine and Evaporative
Certification Guidance document.
EPA Review and Issuance of a
Certificate of Conformity
Upon receiving an application, the EPA
begins its review process. If the review is
positive, a Certificate of Conformity is
issued. If all the required information is
submitted with the application, the turn-
around time for issuing the certificate is
relatively short. However, for a light-duty
vehicle or truck, the EPA may request a test
vehicle for verification purposes. If the
EPA does not request one, the turnaround
time is approximately one month. If the
EPA does request an emissions test vehicle,
and it is made available to the EPA as soon
as it is requested, the turnaround time will
be approximately two additional weeks
from the time the test vehicle arrives at the
EPA test facility. This vehicle must already
be prepped and have the required mini-
mum mileage (minimum of 2,000 miles)
on the alternative fuel system and on the
stabilized emissions control system.
-------
Emission Certification Procedures
Table 3
Index to Locating Emissions Standards in Title 40, Part 86 of the Code of Federal Regulations (CFR)
Light-Duty
Vehicle
Light-Duty
Truck
Heavy-Duty
Otto-Cycle Engine
Heavy-Duty
Diesel Engine
1991
& Later
86.090-8
86.091-9
86.091-10
86.091-11
1993
& Later
86.090-8
86.091-9
86.091-10
86.093-11
1994
& Later
86.094-8
86.094-9
86.091-10
86.094-11
1996
& Later
86.096-8
86.096-9
86.096-10
86.096-11
1997
& Later
86.096-8
86.097-9
86.096-10
86.096-11
1998
& Later
86.098-8
86.097-9
86.098-10
86.098-11
1999
& Later
86.099-8
86.099-9
86.099-10
86.099-11
2001
& Later
86.099-8
86.001-9
86.099-10
86.099-11
2004
& Later
86.099-8
86.004-9
86.099-10
86.099-11
Table 4
Index to Locating Clean-Fuel Vehicle Emissions Standards in Title 40, Part 88 of the
Code of Federal Regulations (CFR)
Light-Duty Vehicle
Light-Duty Truck
Heavy-Duty Otto-Cycle Engine
Heavy-Duty Diesel Engine
1994 & Later
(LEVa,ULEVb,
& ILEVC)
88.104-94
88.104-94
88.105-94
88.105-94
1993 & Later
(ILEVC)
88.311-93
88.311-93
88.311-93
88.311-93
1998 & Later
(ILEVC)
88.311-98
88.311-98
88.311-98
88.311-98
" Low-Emission Vehicle
b Ultra Low-Emission
Vehicle
' Inherently Low-
Emission Vehicle
Fees
The EPA charges a fee for each engine
family certification request; Table 2 con-
tains examples of these fees.
Small volume manufacturers must
either pay the predetermined fee or apply
for a partial waiver. The waiver must be
requested prior to payment of any fee
because it provides only an alternative
method of fee calculation. For aftermarket
conversions, the alternative fee is based
on 1 % of the total value of all vehicles to
be converted. This includes both the value
of the vehicle and the value of the con-
version kit. Vehicle value is determined
using the National Automobile Dealer's
Association (NADA) price guide or other
evidence of the actual market value if the
vehicle is not included in the NADA price
guide. A request for the waiver should be
submitted at the same time as the request
for small volume manufacturer status.
Applications that do not result in a cer-
tification are eligible for a partial refund.
Emissions Certification Standards
Emissions standards are found in vari-
ous sections of the CFR. Tables 3 and 4
summarize the locations by model year
and vehicle or engine type. In addition,
Appendix D summarizes the exhaust
emissions standards.
Vehicles or engines that are converted
to dual-fuel operation must be tested on
and meet the emissions standards for both
fuels. The standards are fuel-specific.
Exhaust emissions standards for LPG
-------
Emission Certification Procedures
Example of Applying Standards and Test Procedures
for CFV Dual-Fuel Aftermarket Conversions
Suppose a manufacturer requests a 1998 model year certifica-
tion for a light-duty truck that it has converted to a CNG/gaso-
line dual-fuel vehicle, and wishes to certify to the LEV
standard. Before the conversion, the original model year of the
truck was 1996, and it was originally certified on gasoline. To
certify it as a dual-fuel vehicle for the 1998 model year, the
manufacturer must perform emissions tests on CNG using the
1998 emissions test procedures for CNG, apply the DFs, and
compare the results to the LEV certification standards.
In addition, the vehicle must be tested on gasoline after con-
version using the 1996 test procedures, the 1996 gasoline
standards and the CFV NMOG and formaldehyde standards for
gasoline. Testing on gasoline must include all of the 1996 test
procedures—cold temperature carbon monoxide (CO), certifi-
cation short test, evaporative, and spitback. Manufacturers do
not need to comply with the new OBD requirements if they
can provide a written technical justification. OBD require-
ments are explained on page 22 of this guide.
Emissions test on an aftermarket conversion being performed on the
Colorado Department of Health and Environment's chassis dynamometer
vehicles are identical to those for gasoline
vehicles. The standards for CNG vehicles
are also identical to the gasoline stan-
dards, except for hydrocarbons. The certi-
fication standards for hydrocarbon
emissions from CNG vehicles are speci-
fied in terms of non-methane hydrocar-
bons instead of total hydrocarbons. CFV
standards include a non-methane organic
gas (NMOG) standard.
Manufacturers who are certifying a
vehicle to tier 1 standards (see sidebar on
page 17) must meet the tier 1 standards
that were in place for the model year in
which the vehicle was originally certified.
This applies to dedicated and dual-fuel
vehicles. Dual-fuel vehicles must be tested
on and meet the applicable standards for
both fuels. Manufacturers certifying to the
CFV standards must meet the standard
that applies to the alternative fuel for the
model year for which certification is being
requested. In other words, a 1996 model
year vehicle converted and being certified
to CFV standards in 1998 must meet the
1998 emissions standards. Dual-fuel vehi-
cles being certified to meet CFV standards
must also satisfy a NMOG and formalde-
hyde standard on the conventional fuel.
They must also comply with the other
conventional fuel standards that were in
effect when the vehicle received its origi-
nal certification. Dual-fuel vehicles cannot
be certified to the ILEV standard. The
sidebar on this page gives an example of
applying emissions standards for CFVs.
EPA's emissions certification standards
vary with vehicle type and weight. For
example, there are specific standards for
light-duty vehicles and trucks, which can
weigh up to 8,500 pounds gross vehicle
weight rating (GVWR). Such vehicles
are tested using a chassis dynamometer
following the applicable light-duty test
-------
Emission Certification Procedures
15
Table 5
Weight Groupings for Light-Duty Trucks
Vehicle Type
Light Light-Duty Truck
Light Light-Duty Truck
Heavy Light-Duty Truck
Heavy Light-Duty Truck
Weight
Class
1
2
3
4
GVWRa
0-6,000 Ib
0-6,000 Ib
6,000-8,500 Ib
6,000-8,500 Ib
LVWb or ALVWC
0-3,750 Ib LVW
3,751-5,750 Ib LVW
3,751-5,750 Ib ALVW
Greater than 5,750 Ib ALVW
" Gross Vehicle Weight
Rating
'' Landed Vehicle Weight
' Adjusted Loaded
Vehicle Weight
Table 6
Heavy-Duty Engine Classifications
Engine Type
Light Heavy-Duty Engine
Medium Heavy-Duty Engine
Heavy Heavy-Duty Engine
Typical Vehicle GVWRa
8,501-19,499 Ib
19,500 Ib- 33,000 Ib
33,001 Ib and greater
Typical
Horsepower Range
70 to 170
170 to 250
Greater than 250
" Gross Vehicle Weight
Rating
procedures. For these tests, exhaust emis-
sions are measured in grams per mile.
Light-duty trucks are further divided into
subgroups according to weight (see Table
5). The tier 0 emissions category has two
subgroups, tier 1 has four, and CFV has
five.
Vehicles that weigh more than 8,500
pounds GVWR are classified as heavy-
duty, and different test procedures and
standards apply. Instead of testing the
vehicle on a chassis dynamometer, the
engine is tested separately using an
engine dynamometer. Exhaust emissions
are measured in grams per brake
horsepower-hour. Refer to Table 6 for
a description of the heavy-duty engine
classifications. Vehicles that weigh
between 8,501 and 10,000 pounds GVWR
can either be tested on a chassis dyna-
mometer as heavy light-duty trucks or
their engines can be tested as heavy-duty
engines (see 40 CFR Part 86.094-1 (b)).
Navistar 466 diesel engine converted to natural gas, being tested on an
engine dynamometer
-------
Emission Certification Procedures
Table 7
Time and Mileage Limits3 for Determining the Tier 1 Standards Applicable to Intermediate and
Full Useful Life Exhaust and Evaporative Emissions
Vehicle/Engine Type
Useful Life for Exhaust Emissions
Intermediate
Full
Useful Life for
Evaporative Emissions
Full
Light-Duty Vehicle
5 years or 50,000 miles
10 years or 100,000 miles
10 years or 100,000 miles
Light-Duty Truck 1 & 2
5 years or 50,000 miles
10 years or 100,000 miles
10 years or 100,000 miles
Light-Duty Truck 3 & 4
5 years or 50,000 miles
11 years or 120,000 miles
11 years or 120,000 miles
Heavy-Duty
Otto-Cycle Engine
none
8 years or 110,000 miles
10 years or 110,000 miles
Light Heavy-Duty
Diesel Engine
none
8 years or 110,000 miles
8 years or 110,000 miles
Medium Heavy-Duty
Diesel Engine
none
8 years or 185,000 miles
8 years or 185,000 miles
Heavy Heavy-Duty
Diesel Engine
none
8 years or 290,000 miles
8 years or 290,000 miles
' Time and mileage
are expressed in
years and miles,
and are one or the
other, whichever
comes first
For light-duty vehicles and trucks, the
EPA also assigns different emissions stan-
dards on the basis of years or miles in
service. These are known as intermediate
and full useful life standards (see "Terms"
in Appendix A for a definition of useful
life), and Table 7 specifies the time and
mileage limits that apply The standards
for full useful life are less stringent
than those for intermediate useful life to
account for the wear and tear on compo-
nents resulting from normal use. In other
words, emissions performance is expected
to deteriorate over time. Compliance with
both the intermediate and full useful life
standards is determined by applying the
appropriate DFs to the emissions test
results (more information about DFs
is found on page 20 of this guide). Com-
pliance with tier 0 emissions standards is
required only at 50,000 miles. Emissions
test results after factoring in the DFs are to
be within the values set for each period.
The useful life period of a vehicle does
not change as the result of conversion. For
example, if a light light-duty truck has
10,000 miles on its odometer at the time of
conversion, its full useful life will end
once its odometer reaches 100,000 miles
(not 110,000 miles).
In addition to testing for exhaust emis-
sions, a number of other tests must also be
performed as part of the EPA Federal Test
Procedures (FTP) for emissions certifica-
tion. These may include multi-day mea-
surement of evaporative emissions and
on-board vapor recovery, as well as the
spitback, refueling, cold temperature CO,
idle, and certification short tests (see CFR
40 Part 86 for details). Results from each
test must be compared to the correspond-
ing certification standards.
Some of the EPA's regulations that gov-
ern emissions standards are being phased
in over time, and others will not become
effective for a number of years. As previ-
ously noted, small volume manufacturers
are exempt from the initial years of the
phase-in of the regulations.
-------
Emission Certification Procedures
17
Evolving Emissions Standards
Emissions standards have been undergoing continuous change for a number of years—
a trend that is expected to continue. This trend is driven by the need for improvements
in air quality, changes in vehicle emissions control technology and, of course, changes
in the fuels themselves.
The EPA and CARB use various names and abbreviations to refer to the various emissions
standards. The EPA currently uses tier 0, tier 1, TLEV, LEV, ILEV, ULEV, and ZEV. These
standards are ranked from less stringent to more stringent (for example, tier 1 is a more
stringent emissions standard than tier 0, and ZEV is the most stringent). The term TLEV
applies to California vehicles only. CARB does not have an ILEV standard, but it does
have a super-ultra-low-emission vehicle (SULEV) standard for medium-duty vehicles.
SULEV is even more stringent than the ULEV standard. Although the name of a standard
may be used for many vehicle types, the actual value can be different for each vehicle
type. For example, the federal tier 1 standards for light-duty vehicles are more stringent
than the federal tier 1 standards for light-duty trucks 2. EPA and CARB emission stan-
dards may differ for the same vehicle type even though they may be described by the
same name.
The EPA has implemented the LEV, ILEV, ULEV, and ZEV standards under the CFF
Program to address air quality issues in cities that do not comply with federal air qual-
ity standards. Although vehicles that meet those standards can be used elsewhere,
fleets within cities that do not meet the air standards are mandated to phase in pur-
chases of new vehicles that comply with LEV and ULEV standards. Vehicle manufactur-
ers certifying vehicles for sale in California are required to phase in sales of TLEV, LEV,
ULEV, and ZEV vehicles.
Appendix A presents additional details on the names and abbreviations of various stan-
dards, and Appendix D summarizes each of the standards by vehicle type.
-------
Emission Certification Procedures
Figure 2:
FTP-75 Using the Urban Dynamometer Driving Schedule
Cold Transient
(Bag 1)
Hot Stabilized
(Bag 2)
10-Minute
Soak
Hot Transient
(Bag 3)
Cold Start
240 480 720 960 1200 1440 1680 1920 2160 2400
Test Time (seconds)
Emissions Testing
Emissions testing is perhaps the most
time-consuming and costly part of the cer-
tification process, but it is also the most
important. We encourage you to become
as familiar with the details of emissions
testing as possible.
Exhaust and Evaporative Testing
Procedures
The procedures that the EPA specifies
for emissions testing of light-duty vehi-
cles and trucks are contained in 40 CFR
Part 86, Subpart B. The exhaust emissions
test procedures follow the EPA FTP 75,
which uses the urban dynamometer dri-
ving schedule (Figure 2). New multi-day
procedures for enhanced evaporative
emissions testing are being phased in.
Although small volume manufacturers
are exempt from the initial years of this
phase-in, they must comply with the
100% requirement for the model year list-
ed in the regulations.
Both the exhaust and evaporative test-
ing procedures must be conducted in a
specific sequence and in temperature-
controlled environments. Several steps in
the evaporative testing procedures for
gaseous fuels differ from those required
for gasoline. For example, different fuel
tank levels are involved, and the supple-
mental two-day diurnal test and the
refueling spitback test are not required for
CNG and LPG. If the vehicle is dual-fuel,
it must be tested on both fuels, including
all the test procedures normally required
for gasoline systems.
The exhaust and evaporative emissions
test procedures for heavy-duty engines
are contained in a number of different
subparts of 40 CFR Part 86 (see Table 8).
Heavy-duty engines are tested on an
engine dynamometer using the transient
engine dynamometer test cycle (Figure 3).
-------
Emission Certification Procedures
Figure 3:
Transient Engine Dynamometer Test Cycle
X
ro
E
120 -
100 -
80 -
T3
O)
S. 60
'& 40 H
LLJ
-a
OJ
_M
"ro
E
20 -
Cold Transient
20-Minute Soak
Hot Transient
Hot Start
Cold Start
i I i ii | i i i | i i i | i i i \ \
400 800 1200 1600 2000
Test Time (seconds)
2400
1 I '
2800
3200
3600
Testing Facilities
The EPA does not certify or approve
emissions laboratories or test facilities, but
it does maintain a list of organizations
with which it has worked on emissions-
related projects. Without making any
endorsements or recommendations, the
EPA makes this list of test facilities avail-
able on its site on the World Wide Web
(see Appendix C). Because a number of
new tests, such as the enhanced evapora-
tive and the cold CO protocols, require
extensive equipment and facilities, be sure
to secure the services of a testing facility
that maintains the appropriate equipment
if such tests are required.
Test Fuels
The EPA provides specifications for the
conventional fuels, as well as for CNG
and LPG, to be used in emissions testing
(see 40 CFR Part 86.113-94). Appendix E
presents details on the specifications of
the CNG to be used in exhaust and evapo-
rative emissions testing. Because this is a
special blend, allow adequate time in your
testing schedule for the laboratory to
obtain an ample supply. Commercial-
grade fuel is suitable for in-service
mileage accumulation. Commercial-grade
LPG is acceptable for exhaust and evapo-
rative testing, and for in-service mileage
accumulation. The formulation of the
CNG and LPG to be used in a testing
protocol must be submitted as part of the
certification application.
Table 8
Index for Locating Heavy-Duty Engine Test Procedures in
Title 40, Part 86 of the Code of Federal Regulations (CFR)
Test Procedure
Gaseous Exhaust
Smoke Exhaust
Evaporative
Particulates
Idle
Altitude
Subpart
N
I
M
N
P
Q
-------
Emission Certification Procedures
Example of Applying Deterioration Factors
Assume the manufacturer has decided to use EPA-assigned DFs for a dedicated Light-duty LPG vehicle
(Enclosure 5 of the EPA Manufacturer's Guidance Letter CD-95-14 provides the assigned DFs used in this
example). The manufacturer completes the baseline testing at 2,000 miles and is given results for the
various regulated exhaust emissions components. These results are then multiplied by the intermediate
and full useful life DFs for each component. The calculated values are then compared to the intermedi-
ate and full useful life standards. If all the components are simultaneously below the values in the
standard, the vehicle is in compliance. If any value exceeds its expected limit, the vehicle is not in
compliance. See Appendix A for an explanation of all abbreviations.
Exhaust Emissions, in grams/mile
Mileage Item THC NMHC CO NOX PM
2,000 miles
50,000 miles
100,000 miles
Test Results
Assigned DFs
Calculated Results
Tier 1 Standard
Assigned DFs
Calculated Results
Tier 1 Standard
0.15
1.7
0.26
0.41
N/Aa
N/Aa
N/Aa
0.12
1.6
0.19
0.25
1.9
0.23
0.31
1.8
1.6
2.9
3.4
1.9
3.4
4.2
0.19
2.0
0.38
0.4
2.3
0.44
0.6
0.01
1.3
0.01
0.08
1.3
0.01 i
0.10
N/A = "not applicable"
Deterioration Factors
Because the performance of emissions
control systems is expected to decline
(i.e., vehicle emissions will increase) with
mileage or hours of service, compliance
with the EPA emissions standards is based
on applying DFs to the base emissions test
results. DFs are used to predict this
expected increase in vehicle emissions at
the useful life mileage points. Refer to
EPA Manufacturer's Guidance Letter CD-
95-14 and Advisory Circular A/C No. 51C
for direction on whether the DF is multi-
plied or added to the baseline emission
test results.
DFs are typically determined by the
manufacturers through tightly controlled
test procedures during which mileage or
hours of service are accumulated and
emissions tests are performed. For light-
duty vehicles, the emissions standards are
specified in terms of emissions limits to be
met at the full or intermediate useful life.
For instance, 1996 model year light-duty
vehicles have one set of emissions stan-
dards to be met at the intermediate useful
life (defined as five years or 50,000 miles)
and another at the full useful life (ten years
or 100,000 miles). The vehicle must comply
with both sets of emissions standards.
-------
Emission Certification Procedures
Compliance with heavy-duty engine
standards is determined in much the same
way. The base emissions measured on a
new engine must be adjusted using the
appropriate DFs before comparing the
results to the emissions standards.
If the manufacturer qualifies for small
volume manufacturer status (see the
sidebar on page 11), some benefits can be
realized from determining and assigning
DFs for gaseous fueled vehicles and
engines. The details are explained in 40
CFR 86.096.14 and Manufacturer's
Guidance Letter CD-95-14. The available
options are:
• Complete durability testing for the
intermediate and full useful life of the
vehicle
• An abbreviated durability test covering
25,000 miles, with more frequent emis-
sions testing
• Using the EPA's assigned DFs or the
DFs already established by the manu-
facturer from previous testing.
The EPA retains the right to rescind the
use of its assigned DFs if subsequent test-
ing indicates that emissions levels are
higher than anticipated. Regardless of
how the DFs are determined, they are
subsequently applied to the baseline
emissions test results of each vehicle to
determine compliance with both its inter-
mediate and full useful life emissions
standards. The sidebar on page 20 gives
an example of how DFs are applied to
baseline emissions test results to deter-
mine compliance with the standards.
Mileage Accumulation Cycle
After converting the test vehicle to
CNG or LPG, and before any emissions
testing, each light-duty vehicle and truck
must accumulate a minimum of 2,000
miles on its odometer. For heavy-duty
engines, a minimum of 62 hours of opera-
tion must be accumulated. These vehicles
or engines are known as emission data
vehicles (EDVs) or engines.
For manufacturers of light-duty vehi-
cles and trucks who choose to generate
their own DFs by conducting durability
testing, two methods may be applied to
accumulate the required mileage.
The first method is specified in 40 CFR
Part 86, Appendix IV ("Durability Driving
Schedule"). Under this protocol, a vehicle
is driven on a 3.7-mile course at various
speeds (up to 70 miles per hour) for a
specified period of time. The vehicles tested
are referred to as durability data vehicles
(DDVs). The second method, which
requires prior approval from the EPA, is
outlined in EPA Advisory Circular No.
37-A. Under this protocol, mileage can be
accumulated on test tracks, dynamome-
ters, or public roads as long as the mileage
accumulation meets the criteria contained
within No. 37-A. The maximum speed is
55 miles per hour over a 3.7-mile cycle.
Maintenance Schedule during
Testing and Data Collection
EPA regulations specify the minimum
maintenance interval for emissions
control components. This schedule also
applies to any maintenance performed
during the mileage accumulation phase of
durability testing. This information is
contained in the EPA's information pack-
age and in 40 CFR 86.094-25. Maintenance
may not be performed more frequently
than specified in the regulations or the
manufacturer's maintenance schedule.
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Emission Certification Procedures
Table 9
Required Number of Emissions Tests (FTP 75) for Dedicated Alternative Fuel Vehicles
Option for Determining
Deterioration Factors (DFs)
On the
Durability Data Vehicle
On the
Emission Data Vehicle
Full mileage accumulation
Minimum of 2'
Abbreviated mileage accumulation
5 required, 6 optional
Manufacturer's own DF (previous history)
0
EPA-assigned DF
" A minimum of two
are required, but
additional tests
equally spaced
in mileage are
encouraged in order
to confirm the DF.
Six or seven tests
would provide a
more meaningful
and reliable
representation of
this value.
Required Number of Tests for
Light-Duty Vehicles and Trucks
The required number of emissions tests
varies depending on which option is cho-
sen to develop DFs. It is necessary to use
only one DDV per engine family to estab-
lish the DFs and one EDV per engine fami-
ly to measure emissions levels. The DFs are
applied to the results of the EDV and are
used to calculate the intermediate and full
useful life values. Results of all tests must
be supplied to the EPA. Table 9 outlines the
required number of tests for various situa-
tions for dedicated CNG and LPG vehicles.
For dual-fuel vehicles, the number of tests
shown in Table 9 must be doubled.
Because emissions test results are known
to be variable depending on the vehicle
being tested, it is wise to conduct more
tests than the minimum number required
to confirm the results.
Carry-Across and Carry-Over
"Carry-across" is the term used for
applying emissions results generated for
one engine family to another family from
the same model year. Similarly, "carry-
over" is the term used for applying emis-
sions results from an engine family in one
year to an engine family in the succeeding
model year. EPA Advisory Circular No.
17F sheds more light on these concepts.
The circular explains the EPA's position
on the suitability of carrying results from
test vehicles and durability data vehicles,
as well as fuel economy, to other models
in the same or later years. DFs are carried
over more frequently than the baseline
emissions test results.
Corporate Average Fuel Economy
(CAFE) Testing and the Gas
Guzzler Tax
Only new light-duty vehicles and
trucks are subject to CAFE, fuel economy
labeling, and the "gas guzzler" tax.
Aftermarket conversions need not comply
with these regulations.
On-Board Diagnostics (OBD)
The EPA has established regulations
governing OBD systems for light-duty
vehicles and trucks. These regulations
require that certain components in the
emissions control system be monitored for
proper performance over the vehicle's life-
time. Typically, the vehicle's electronic con-
trol unit (ECU) is programmed to monitor
the function of specific emissions control
systems through signals it receives from
various engine control sensors and actua-
tors, such as the exhaust gas oxygen
sensor. When unacceptable deterioration
or malfunctions occur, a diagnostic trouble
code is stored in the ECU, and a message
light is illuminated on the vehicle's dash-
board (for example, "Service Engine Soon"
or "Check Engine"). These systems were
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Emission Certification Procedures
originally designed by the vehicle manu-
facturers to detect and diagnose problems
when electronic control systems replaced
mechanical systems. The EPA now requires
light-duty vehicles and trucks to be equip-
ped with such systems in order to help
reduce emissions caused by malfunction-
ing emissions controls.
The latest OBD requirements, known as
federal OBD regulations, are virtually the
same as California's OBD II regulations.
All light-duty vehicles and trucks pro-
duced during and after the 1996 model
year must meet these regulations. Federal
OBD regulations require that virtually all
the vehicle's emissions control system
components be monitored, including cata-
lyst efficiency, engine misfires, closed loop
fuel system performance, oxygen sensor
performance, and exhaust gas recircula-
tion. Currently, CNG and LPG vehicles
can receive justifiable waivers from the
federal OBD requirements up to and
including the 1998 model year. Even with
this waiver, the OBD system must remain
intact while the vehicle is operating on
gasoline. Under an EPA notice of pro-
posed rule-making published in May
1997, the EPA is proposing to extend the
justifiable waivers. Here is an excerpt
from the notice:
"EPA is proposing to extend the current
flexibility provisions for alternative fuel
vehicles through the 2004 model year.
Such vehicles will be expected to comply
fully with the OBD requirements during
gasoline operation (if applicable), and
during alternative fuel operation except
where it is technologically infeasible to do
so. Any manufacturer wishing to utilize
this flexibility provision must demon-
strate technological infeasibility concerns
to EPA well in advance of certification
application."
Labels, Decals, and
Maintenance Schedule
After it has been converted, each vehicle
or engine must display a supplemental
emissions control label. This label must be
placed adjacent to the original emissions
control information label. The specific
requirements governing the appearance
and placement of the label are contained
in 40 CFR Part 85.505. The new label must
indicate that the vehicle has been convert-
ed to operate on an alternative fuel; it must
specify the equipment manufacturer's and
the installer's names, addresses, and tele-
phone numbers; and it must present all
conversion-related details, such as the
model year, date of conversion, mileage at
conversion, and changes made to the vehi-
cle (for example, tuneup specifications).
Additional labeling requirements for
CFF vehicles are found in 40 CFR Part 88.
Part 88 requires that the label in Part 86 also
stipulate whether the vehicle or engine in
question is LEV- or ULEV-compliant and
meets all the requirements of Part 88.
Heavy-duty vehicles, as defined in Part
88, are also required to display a label (see
40 CFR 88.305-94) if they are not covered
by the requirements specified in Part 86.
Providing that certain criteria are met,
vehicles that are ILEV-compliant may be
able to take advantage of transportation
control measure exemptions such as using
high-occupancy vehicle (HOV) lanes. An
example of such criteria is the require-
ment to mount special decals on the
exterior of the vehicle.
Samples of these labels and decals
must be submitted to the EPA before a
Certificate of Conformity can be issued.
In addition to providing vehicle labels
and decals, manufacturers are to provide
vehicle owners with the maintenance
schedule for emissions-related items (see
40 CFR Part 86.094-25(b)(l)).
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Emission Certification Procedures
Record Keeping
Manufacturers are required to keep
detailed certification information for a
period of eight years from the date on
which the Certificate of Conformity is
issued. Manufacturers must also keep
detailed records of the number of such
vehicles that are converted (i.e., the num-
ber of conversion kits that are sold), but
the eight-year period starts at the end of
the model year. The EPA's requirements
for record retention are outlined in 40 CFR
Parts 86.094-7 and 86.096-7. All such infor-
mation must be made available to the EPA
on request.
Manufacturers are further responsible
for maintaining conversion records
on vehicles converted under the CFF
Program (see 40 CFR Part 88.306-94 (f)).
These records, which must include the
following information, must be kept for a
period of five years from the date of
conversion.
• Engine or vehicle make, model,
model year, and vehicle identification
number (VIN)
• Certification number of the conversion
configuration
• Brand name and numbers of parts
used in the conversion
• Date of the conversion
• Facility where the conversion equip-
ment was installed
• Results of post-conversion emissions
testing.
Warranty
The EPA's regulations require that man-
ufacturers provide both an emissions
design and defect warranty and an
emissions performance warranty for
light-duty vehicles and trucks. Effective
with the 1995 model year, the warranty
period is two years or 24,000 miles,
whichever comes first. For EPA-specified
major emissions control components such
as the catalytic converter, the electronic
emissions control unit, and an on-board
emissions diagnostic device, the warranty
period is eight years or 80,000 miles,
whichever comes first.
For heavy-duty Otto-Cycle engines and
light heavy-duty diesel engines, manufac-
turers must provide a design and defect
warranty of five years or 50,000 miles,
whichever comes first; for medium- and
heavy heavy-duty diesel engines, five
years or 100,000 miles, whichever comes
first. If the manufacturer provides a
longer period on the basic mechanical
warranty to the engine family, this period
must also extend to the emissions warranty.
The warranty must cover the labor to
diagnose and repair or replace the part as
well as the cost of any replacement parts.
The certification application for light-duty
vehicles and trucks must contain the pro-
visions of the warranty policy to be
offered.
It is also important to note that the OEM
continues to be responsible for those parts
of the vehicle that retain their original
function after conversion. In addition, the
warranty period of an af termarket conver-
sion does not need to extend past that of
the original vehicle or engine. For exam-
ple, if a heavy-duty Otto-Cycle engine has
5,000 miles on its odometer at the time of
conversion, its design and defect warran-
ty period will end once its odometer
reaches 50,000 miles (not 55,000 miles).
-------
Emission Certification Procedures
Audit and In-Use Surveillance
To ensure that conversion equipment is
designed, built, and installed so as to
allow vehicles to meet emissions stan-
dards throughout their useful lives, the
EPA has established a number of compli-
ance programs that it enforces as part of
its emissions regulations. For example,
during the certification process, the EPA
may evaluate the emissions control design
of all conversion equipment. It also con-
ducts selective enforcement audits of
product assembly lines and equipment
installers, and it evaluates vehicles during
in-use operations. Vehicles and engines
can be recalled if the EPA determines that
they are not meeting the useful life stan-
dards to which they have been certified.
Responsibilities of Distributors
and Installers
The manufacturer of record on the
Certificate of Conformity is responsible
for ensuring that all vehicles being
converted comply "with the terms of the
certificate. The manufacturer's interests
will be best served by providing the
installer with a detailed parts list, com-
plete installation instructions, all exam-
ples of proposed labels and decals, vehicle
maintenance schedules, post-conversion
inspection and testing requirements/
methods, information on record-keeping
plans, and training for proper equipment
installation.
Establishing a quality control program
for the entire vehicle conversion process is
also advisable. The installer must ensure
that the vehicle being converted is of the
same engine family as that for which the
Certificate of Conformity has been granted.
The installer must follow installation
instructions exactly with no component
substitutions.
Failure to install the conversion system
on the correct engine family, installing the
wrong parts, or improperly installing the
correct parts may subject the manufacturer
and/or the installer to a civil penalty of up
to $25,000 per vehicle or engine.
Certification under the CFF Program
requires that the manufacturer provide
installation instructions to the installer(s)
(see 40 CFR Part 88.306-94). The manufac-
turer must also provide the name of the
installer(s) to the EPA as part of the certifi-
cation application. Only those installers
listed on the application may perform
conversions.
Vehicles and engines that are part of the
CFF Program and are converted under the
auspices of small volume manufacturer
status must pass a post-conversion CO
emissions test (see 40 CFR Part 88.306-94).
There are two options for conducting the
test: (1) for light-duty vehicles and trucks,
follow the inspection and maintenance
requirements and procedures applicable
to the geographic area in which the vehi-
cle will be operated; and (2) conduct a
specific two-speed idle test, which must
be conducted using certification fuel. Both
methods require that dual-fuel vehicles be
tested on each fuel.
Under certain conditions, fleet operators
who are converting to an ILEV-compliant
vehicle may be able to take advantage of
transportation control measure exemp-
tions such as using HOV lanes. First, fleets
must verify that they are eligible for
exemption from transportation control
measures. If the fleet qualifies and wants
to take advantage of the HOV lanes, the
installer must also place three ILEV decals
on the exterior of the vehicle to clearly sig-
nify ILEV status. Engines used in heavy-
duty vehicles weighing more than
26,000 pounds may not qualify for this
exemption.
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Emission Certification Procedures
Liabilities
Liabilities are incurred when all provisions of the CAA are not
met. Section 205 (a) (see below) stipulates that penalties will
be imposed on companies and individuals that do not comply
with its provisions.
(a) Violations any person who violates sections 203 (a) (1),
203 (a) (4), or 203 (a) (5) or any manufacturer or dealer who
violates section 203 (a) (3) (A) shall be subject to a civil
penalty of not more than $25,000. Any person other than a
manufacturer or dealer who violates section 203 (a) (3) (B)
shall be subject to a civil penalty of not more than $2,500.
Any such violation with respect to paragraph (1), (3) (A), or
(4) of section 203 (a) shall constitute a separate offense with
respect to each motor vehicle or motor vehicle engine. Any
such violation with respect to section 203 (a) (3) (B) shall
constitute a separate offense with respect to each part or
component. Any person who violates section 203 (a) (2) shall
be subject to a civil penalty of not more than $25,000 per day
of violation.
If conversion equipment is being
installed under the provisions of the
addendum to Memo 1A (see page 7
of this guide) rather than a Certificate of
Conformity, the installer must request
and retain a representation from the
manufacturer (or any party that takes on
demonstration requirements in accor-
dance with the addendum) that the con-
version system meets the addendum's
requirements for the specific engine fam-
ily being converted. The installer should
request installation instructions, which
must be followed exactly with no compo-
nent substitutions. The installer should
also ensure the conversion equipment is
being installed on vehicles of the same
engine family on which testing was per-
formed. The installer must retain records
for each vehicle converted—the cus-
tomer's name and address, the VIN, the
make and model year of the vehicle, the
date of installation, the installer, and the
manufacturer's representation of confor-
mance to the addendum. Retaining the
vehicle's odometer reading at the time of
installation, the brand name(s) and part
numbers of all equipment installed, and
the calibration settings is also advisable.
Distributors should follow a similar
process. If they did not perform the emis-
sions testing, they should request and
retain representation that the conversion
system meets the addendum's require-
ments for the given engine family. They
should also keep information on each con-
version kit sold, the name of the pur-
chaser, all part numbers, the date of sale,
and the number of systems sold.
Clean-Fuel Vehicles and Mobile
Emissions Reduction Credits
Under the provisions of the CAA,
mobile emissions reduction credits may
be granted for fuels and vehicles that meet
the CFF Program requirements (see 40
CFR Part 88). To receive mobile emission
reduction credits, the fleet must first
exceed the minimum requirements of the
CFF Program. This program applies to
light-duty vehicles and trucks, heavy
light-duty trucks, and heavy-duty engines
that are certified to the LEV, ILEV, and
ULEV standards. The original implemen-
tation date was model year 1998, but it has
been recently postponed to model year
1999, although cities may opt in earlier.
Those cities that are in non-attainment
with federal air quality standards, as out-
lined in the CAA, are elgible for the federal
emissions reduction credits program.
Fleets operating within these cities are
required to purchase CFVs as stipulated
in 40 CFR Part 88. Such vehicles must be
certified to CFV emissions standards
using the procedures outlined in 40 CFR
Parts 86 and 88.
In addition to qualifying for credits,
CFVs are also exempt from a number of
transportation control measures (see 40
CFR Part 88.307-94) in non-attainment
areas. For example, vehicles that are ILEV-
compliant may qualify to use HOV lanes.
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Emission Certification Procedures
Certification by the
California Air Resources Board
General Information
In California, CARB is responsible for
the emissions certification on all motor
vehicles. The California Health and Safety
Code authorizes CARB to establish emis-
sions certification procedures and to
certify fuel systems that have met its
requirements. Further, the California
Vehicle Code prohibits the installation,
sale, offering for sale, or advertisement of
any motor vehicle pollution control
device or system that alters or modifies
the original design or emissions perfor-
mance without CARB's approval.
California's certification process for
aftermarket conversions is similar to the
EPA's, but there are some significant dif-
ferences. In some ways, it is more strin-
gent than the EPA's; in other ways, it is
not. Some of the major differences are:
• CARB certification applies to the model
year in which the vehicle was originally
produced, instead of the year or model
year in which the vehicle is converted
• CARB does not impose a time limit on
the terms of the certification
Who to Contact
California Environmental Protection Agency
Air Resources Board
Mobile Source Operations Division
Aftermarket Parts Section
9528 Telstar Avenue
P.O. Box 8001
El Monte, CA 91731
Telephone: (818) 575-6800
Fax: (818) 575-6685
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Emission Certification Procedures
California
Table 10
California Certification Procedures for Aftermarket Conversions
Model Year of Vehicle or Engine
Title of Certification Procedure
All Model Years
California Certification and Installation Procedure for Alternative
Fuel Retrofit Systems for Motor Vehicles Certified for 1994 and
Subsequent Model Years and for All Model Year Motor Vehicle
Retrofit Systems Certified for Emission Reduction Credit
• Medium- and heavy-duty vehicles can
be certified in California using emis-
sions test results obtained on a chassis
dynamometer (instead of an engine
dynamometer)
• CARB's requirements for durability
testing are considerably different than
the EPA's.
Regulations
The procedures for certifying CNG or
LPG aftermarket vehicle conversions in
California are contained in California Code
of Regulations, Title 13, Section 2030.
Various procedures have been in effect
since 1975. See Table 10 for the title of the
current certification procedure.
Prior to the release on September 4,
1997, of the EPA addendum to Memo-
randum 1A (see page 7), California used
the procedure entitled "California Exhaust
Emission Standards and Test Procedures
for Systems Designed to Convert Motor
Vehicles Certified for 1993 and Earlier
Model Years to Use Liquefied Petroleum
Gas or Natural Gas Fuels" for 1993 and
older vehicles. However, the EPA no
longer accepts that procedure as a reason-
able basis to believe that emissions perfor-
mance has not been adversely affected.
What Does Certification Apply To?
The certification procedure identified in
Table 10 applies to vehicles that have
already been registered with the California
Department of Motor Vehicles. Other pro-
cedures must be followed for new vehi-
cles that have not yet been registered.
The procedure applies to dedicated,
dual-fuel, and bi-fuel aftermarket conver-
sions for light-duty vehicles and trucks,
medium-duty vehicles, and heavy-duty
engines/vehicles. CARB's definition of
dual-fuel is the same as the EPA's (see
page 2 or the glossary). CARB defines "bi-
fuel" as any vehicle or engine with two
separate fuel systems. Bi-fuel vehicles or
engines can run on either the conventional
fuel or on the conventional fuel and the
alternative fuel simultaneously. An exam-
ple of this type of vehicle/engine is a
heavy-duty engine converted to run on
diesel and CNG (or LPG) with a pilot-
ignition system. In pilot-ignition systems,
a small amount of diesel fuel starts and
maintains combustion and CNG is added
once power is required.
An alternative test method is available
for certifying medium- and heavy-duty
engines in vehicles without removing the
engine from the vehicle (see the section on
emissions testing on page 31). If the alter-
native method is used, the vehicle does
not qualify for mobile source emission
reduction credits (MSERCs; see page 35
for a discussion).
Each certification applies to a specific
engine family, and the manufacturer may
only convert vehicles from the engine
family specified (see the sidebar on page 9
for an explanation of engine families).
CARB uses the engine family names
defined by the EPA, but does not change
the engine family name after the vehicle
has been converted.
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Emission Certification Procedures
At the end of a successful certification
process, CARB will issue an Executive
Order (EO) that authorizes the applicant
to proceed with vehicle conversions. The
EO permits the manufacturer and in-
stallers to convert vehicles of the engine
family specified in the EO. The EO does
not include a date restriction beyond
which vehicles can no longer be con-
verted—it remains in effect for as long as
the applicant wishes to convert vehicles of
the particular model year in question.
Introduction to the
Certification Process
The flow chart in Figure 4 illustrates the
steps necessary to obtain emissions certifi-
cation in California, using full durability
testing. All steps must be completed
before an EO can be issued. Alternative
methods can be used for durability testing
to determine DFs (see Appendices F
through I for illustrations). DFs are ex-
plained on page 20 of this guide.
California's certification process in-
cludes the development and acceptance of
both a certification plan and an applica-
tion. CARB generally requires one to two
weeks to review and approve the certifica-
tion plan. Approving the certification
application and issuing the EO takes
about two months. If the manufacturer
fails to supply all the required informa-
tion, more time may be needed.
Certification Plan, Application,
and Fees
As the first step in the certification
process, the manufacturer must develop a
certification plan for all the engine fami-
lies that it intends to certify during the
year. The plan must include the emissions
standards applicable to each engine fam-
ily, as well as information about the devel-
opment of durability data, the format to
be followed during durability testing, and
the name of the laboratory that will con-
duct the emissions testing. The manufac-
turer should provide all relevant details
on the conversion equipment, including
the operating characteristics, a parts list,
and installation instructions or manual.
The plan should be as comprehensive as
possible. Before any testing can begin, the
plan must be submitted to CARB for
review and approval.
Once CARB approves the certification
plan, testing may begin. The testing must
be accomplished according to the proce-
dures that CARB approved in the certifi-
cation plan. When testing is complete, the
manufacturer may submit an application
for certification, submitting a separate
application for each engine family.
Although CARB does not have a set for-
mat for the certification application, it
does have a list of items that must be
included. For more information, contact
CARB at the address given on page 27.
California does not charge a fee for cer-
tifying after market vehicle conversions.
Emissions Standards
The emissions standards that apply to
the certification of aftermarket conver-
sions in California are those that were in
effect for the model year of the vehicle
being certified. For example, if a manufac-
turer wishes to certify a 1996 model year
vehicle from a particular engine family,
the applicable emissions standards are
those that were in effect for the 1996
model year. There are some exceptions for
medium- and heavy-duty vehicles. Refer
to Section 5 of "California Certification
and Installation Procedures for Alternative
Fuel Retrofit Systems for Motor Vehicles
Certified for 1994 and Subsequent Model
Years and for All Model Year Motor
Vehicle Retrofit Systems Certified for
Emission Reduction Credit."
-------
30
California
Certification plan (EF line-up)
Yes
Delete
EF from line-up?
Emission
Certification
Procedures
Conduct 4,000 mile testing and accumulate miles
No ^ CananV
unscheduled maintenance
Complete durability demonstration
Submit engineering report and
perform unscheduled maintenance
Validate OBD compliance
Submit application (emissions data,
warranty, label, instructions, etc. . .)
Figure 4:
California Certification
Process for Aftermarket Conversions
O
Manufacturer
Action
CARB
Action
BAR
Action
Abbreviations
CARB California Air Resources Board
BAR Bureau of Automotive Repair
EF Engine Family
EO Executive Order
OBD On-Board Diagnostics
-------
Emission Certification Procedures
Table 11
California
Index to California Exhaust, Evaporative, and Refueling Emissions Standards
Emissions Type
Vehicle Type
Name
Exhaust
Passenger Car,
Light-Duty Truck,
Medium-Duty Vehicle
California Exhaust Emission Standards and
Test Procedures for 1988 and Subsequent Model
Passenger Cars, Light-Duty Trucks, and
Medium-Duty Vehicles
Exhaust
Heavy-Duty Engine,
Heavy-Duty Vehicle (Otto-Cycle)
California Exhaust Emission Standards and
Test Procedures for 1987 and Subsequent Model
Heavy-Duty Otto-Cycle Engines and Vehicles
Exhaust
Heavy-Duty Engine,
Heavy-Duty Vehicle (Diesel-Cycle)
California Exhaust Emission Standards and
Test Procedures for 1985 and Subsequent Model
Heavy-Duty Diesel-Engines and Vehicles
Evaporative
Passenger Car, Light-Duty Truck,
Medium-Duty Vehicle,
Heavy-Duty Vehicle
California Evaporative Emission Standards and
Test Procedures for 1978 and Subsequent Model
Motor Vehicles
Refueling
Passenger Car, Light-Duty Truck,
Medium-Duty Vehicle with GVWRa
less than or equal to 8,500 Ib
California Refueling Emission Standards and
Test Procedures for 1998 and Subsequent Model
Motor Vehicles
Table 11 identifies the different
California standards that apply to
exhaust, evaporative, and refueling emis-
sions. A conversion kit can only be certi-
fied to the same or more stringent
standard as the one to which the vehi-
cle/engine was originally certified. For
instance, if the vehicle was originally certi-
fied to LEV emissions standards, the con-
version can be certified to LEV or the more
stringent ULEV standards, but not to the
less stringent TLEV standards. Measured
emissions must remain within the applica-
ble standards for the useful life of the vehi-
cle (see Appendix A for a definition of
useful life). In the case of dual-fuel vehi-
cles, both fuels must meet the standards.
For "credit-generating vehicles" (vehicles
that earn MSERCs; see the discussion on
page 35), the certification standards
applicable to both fuels under dual-fuel
operation must not be more than one
tier (see the sidebar on page 17) apart.
Examples of standards that are one tier
apart are TLEV for gasoline and LEV for
propane, or LEV on gasoline and ULEV on
CNG. See Appendix D for a summary of
exhaust emissions standards.
Emissions Testing
For aftermarket conversions, vehicles
are divided into the following three cate-
gories to determine the emissions testing
method:
Category I — light-duty passenger cars,
trucks, and medium-duty vehicles origi-
nally certified on a chassis dynamometer
Category II — vehicles weighing 14,000
pounds GVWR or less that were not
originally certified on a chassis dyna-
mometer
Category III — vehicles weighing more
than 14,000 pounds GVWR.
The documents referenced in Tables 10
and 11 contain the processes for conduct-
ing the emissions testing. Passenger cars
and light-duty trucks are tested using the
' Gross Vehicle
Weight Rating
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California
Emission Certification Procedures
Table 12
" Mobile Source
Emission Reduction
Credits
b Will not generate
Mobile Source
Emission Reduction
Credits
Test Procedures Required in California for Vehicle Categories
Vehicle Category
I
II
III
Test Procedure Required
to Generate MSERCs3
FTP 75
Heavy-Duty Transient
Heavy-Duty Transient
Other Acceptable
Test Procedures15
none
FTP Chassis Dynamometer Cycle
Chassis Dynamometer Cycle
FTP 75 driving schedule (see Figure 2 on
page 18). This same procedure can be used
for vehicles in Category II and a suitable
chassis dynamometer test for Category III,
but they would not qualify for MSERCs.
To qualify for MSERCs, Category II and III
vehicles must be tested using heavy-duty
transient procedures on an engine dyna-
mometer. Table 12 summarizes the testing
procedures that can be used for each vehi-
cle category.
Like the EPA, CARB does not approve
or recommend testing laboratories or
facilities, although it does maintain a list
of laboratories with which it has worked.
If your company plans to use a facility
that is not on CARB's list, provide de-
tailed information about that labora-
tory and its qualifications as part of the
certification plan. A number of new tests,
such as enhanced evaporative testing and
the cold CO procedure, require special-
ized equipment and facilities.
Following the installation of conversion
systems, vehicles must be driven 4,000
±100 miles to stabilize emission rates
before exhaust and evaporative emissions
testing can be conducted.
CARB requires that certification-grade
fuel be used for emissions testing of CNG
and LPG conversions. Commercial-grade
fuel is acceptable for use during mileage
accumulation for durability testing.
Certification and commercial grades of
fuel are compared in Appendix E.
Dedicated CNG vehicles are exempt
from evaporative emissions testing. Dual-
fuel CNG vehicles, on the other hand,
must comply with the applicable evapora-
tive emissions standard when operating
on gasoline. LPG vehicles must undergo
evaporative emissions testing. The applic-
able standards and procedures are provid-
ed in "California Evaporative Emission
Standards and Test Procedures for 1978
and Subsequent Model Motor Vehicles." If
the vehicle is dual-fuel, both fuels must be
tested. In lieu of actual testing, manufac-
turers may provide an engineering analy-
sis of the impact of their systems on
evaporative emissions. This analysis must
demonstrate that the aftermarket fuel sys-
tem or any other modification to the vehi-
cle does not result in moving, removing,
or recalibrating the OEM's gasoline evap-
orative control system.
If the vehicle and its engine family
were originally certified to the new
California enhanced evaporative emis-
sions standards, the converted vehicle
must also comply with these standards.
These new standards are more involved
than the previous evaporative standards
and require both a three-day and a two-
day diurnal test plus a running loss test.
One test vehicle is required for each
engine family to be certified. If the CARB-
approved certification plan permits the
use of derived DFs, only one test is
required per vehicle per fuel after accu-
mulating 4,000 miles following conver-
sion. This emissions test establishes a
baseline on which to apply the DFs. The
test vehicle is known as the EDV.
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Emission Certification Procedures
If the CARB-approved certification plan
requires the manufacturer to establish
DFs, durability testing will be required.
Durability data must be obtained on only
one vehicle from each engine family to be
certified. This vehicle is referred to as the
DDV. Provisions that allow "carry-across"
(see page 22) of previously established
DFs are explained in the next section. The
minimum number of tests to be conducted
on the DDV depends on whether or not it
must comply with intermediate useful life
standards (see Appendix A for a definition
of useful life). If the vehicle must comply
with intermediate useful life standards, it
must be tested three times per fuel—once
at its baseline mileage level (4,000 miles
after conversion), once after it accumu-
lates its intermediate useful life mileage,
and once after it accumulates its full useful
life mileage. If the vehicle is not required
to comply with intermediate useful life
standards, only two tests are required—
one at the baseline mileage and one at the
full useful life mileage.
Many manufacturers conduct more fre-
quent tests on their DDVs to discover
whether they have any early emissions
problems, and to ensure more reliable
trends with which to establish DFs. Under
some of the certification procedures, the
test vehicle and the DDV can be one and
the same (see the discussion below about
durability testing).
Options for Durability Testing, and
Carry-Across and Carry-Over
Provisions
Several alternative procedures for
demonstrating the full useful life durabil-
ity of emissions for each engine family are
available. For example, under certain cir-
cumstances, it may be possible to apply a
gasoline DF to the alternative fuel emis-
sions results (gasoline DFs for various
OEM vehicles are available from CARB).
The process is outlined in CARB's
Manufacturers Advisory Correspondence
#95-05. The flow chart in Appendix F
illustrates the complete certification
process when it entails a request for, and
use of, gasoline DFs.
Remember that with this substitute
procedure, a full in-use durability test on
the alternative fuel is still required. First,
the manufacturer must test and record
data for emissions, catalytic converter
temperatures, and air/fuel ratio calibra-
tions on gasoline and the alternative fuel
at 4,000 miles. Next, the same tests must
be repeated for the alternative fuel at the
intermediate and full useful life mileages.
After the manufacturer has completed the
testing, CARB will evaluate the alterna-
tive fuel calibration control capability and
the thermal degradation of the catalyst,
and make the appropriate comparisons. If
the same conversion equipment is to be
used on a wide array of vehicles, the dura-
bility test should be conducted using a
"worst-case" vehicle. Usually, this vehicle
will have the most advanced fuel meter-
ing technology, and will be certified to the
most stringent emissions standard.
CARB's Manufacturers Advisory Cor-
respondence #95-05 outlines another
method to demonstrate useful life dura-
bility. This particular method uses carry-
across provisions. It also requires a full
in-use demonstration of durability.
Appendix G contains a flow chart illus-
trating the steps necessary under this
procedure.
CARB has also implemented a program
that allows manufacturers to apply
derived DFs to the emissions test results
from passenger cars, light-duty trucks,
and medium-duty vehicles. These DFs
must be confirmed through durability
testing, but the testing can be accom-
plished over a two-year period. Under this
scenario, an EO would be issued based on
the use of derived DFs, with subsequent
review after full durability testing is com-
plete. With this approach, manufacturers
may convert vehicles before the full dura-
bility testing is completed. Manufacturers
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California
assume liability for a recall if the durabil-
ity data do not confirm the derived DFs.
The process is outlined in CARB's Manu-
facturers Advisory Correspondence #95-
10, and the necessary steps are illustrated
in Appendix H of this guide.
A similar program is available for
heavy-duty engines using derived DFs.
The program is outlined in CARB's Manu-
facturers Advisory Correspondence #95-
07, and Appendix I illustrates the neces-
sary steps.
On-Board Diagnostics (OBD)
Requirements
An introduction to OBD is provided on
page 22. California adopted its OBD II
regulations in 1989, and implementation
began in 1994. According to these regula-
tions, aftermarket conversion of vehicles
must not result in the disabling of the
OBD systems—these systems must
remain fully functional. Applications for
waivers of this requirement for CNG and
LPG vehicles may be approved if the
manufacturer can provide a significant
engineering analysis to justify foregoing
the specific monitoring requirements.
Currently, applications for waivers will be
available for conversion of vehicles
through the end of model year 2004. CNG
and LPG vehicles must still comply with
the less stringent OBD I regulations.
General Emissions Warranty
Coverage
California's procedure for aftermarket
conversions requires both the manufac-
turer and the installer to provide a warran-
ty on emissions-related components. The
warranty must cover all parts and labor,
including those associated with problem
diagnosis. Two levels of warranty cover-
age must be offered: (1) three years or
50,000 miles, whichever comes first, for
all components; and (2) seven years or
Emission Certification Procedures
70,000 miles, whichever comes first, for
high-priced components. The value of
high-priced components includes the price
of the component and the labor for diag-
nosis and repair. CARB establishes a value
of the high-priced components annually
and disseminates this information through
a Manufacturers Advisory Correspon-
dence. For the 1998 model year, the value
for high-priced components is $400. The
warranty periods begin on the date of con-
version, and the vehicle mileage at that
time is considered to be zero.
Owner's Manual, Maintenance
Schedule, and Vehicle Labels
The manufacturer or installer must pro-
vide the customer with an owner's manual
that includes details about the conversion
system, refueling procedures, mainte-
nance, warranty, and servicing locations.
CARB requires that a label providing
certain information to the consumer be
affixed under the hood of each converted
vehicle. This label must be situated beside
or close to the OEM emissions control
label, and it must include information
about the manufacturer and installer of
the conversion equipment, emissions cer-
tification information, details of the instal-
lation procedure, alterations made to the
original vehicle, and a vacuum hose rout-
ing diagram.
Record Keeping
Installers are required to retain certain
information, listed below, in their files
about each converted vehicle:
• Vehicle identification number (VIN)
• California license plate number
• Vehicle owner, address, and phone
number
• Installation date
• EO number.
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Emission Certification Procedures
Installers must also supply the same
information to the manufacturer, who in
turn is required by regulation to retain it.
All information must be kept for six years
after the date of conversion.
Audit, In-Use Surveillance, and
Liabilities
In addition to other kinds of testing,
CARB may require manufacturers to con-
duct in-use enforcement emissions testing.
The enforcement testing may be the result
of a number of different circumstances,
including poor emissions performance
reported by CARB's field organization. If
required, such testing must be conducted
on a minimum of ten vehicles per certified
kit/engine family. If the results are unsat-
isfactory, CARB may request that the man-
ufacturer initiate a recall. Section 8 ("In-
Use Enforcement Test Requirements") of
the certification procedure contains addi-
tional details.
Responsibilities of the Installer
The installer must provide a warranty
statement, preapproved by CARB, to the
owner of each converted vehicle. The pur-
pose of the warranty is to guarantee that
the conversion system has been installed
according to the manufacturer's installa-
tion instructions or manual and its EO.
The minimum coverage period is for three
years or 50,000 miles, whichever comes
first, and it applies to both parts and labor.
Installers are required to fill out a por-
tion of the under-hood emissions control
label prior to its application. They are also
required to retain certain conversion-
related information (see the discussion of
record keeping on page 34 of this guide).
After each conversion is completed, the
installer must transport the vehicle to a
Bureau of Automotive Repair (BAR)
Referee Smog Check Station for inspec-
tion and testing. It may be helpful to bring
a copy of the EO to BAR for reference.
CARB has an alternative inspection proce-
dure to permit one out of ten vehicles to
be inspected at the BAR station. The
installer must obtain prior approval from
CARB to use this alternative. If the vehicle
passes the BAR inspection, it is issued a
decal (different from the under-hood
label), which is generally installed on the
door jamb.
Penalties and Liabilities
Manufacturers that do not comply with
either the California Health and Safety
Code or the California Vehicle Code are
subject to fines and vehicle recalls.
Although manufacturers that have
received EOs are exempt from the tamper-
ing provisions of the California Vehicle
Code, they are still subject to recalls if
vehicles fail subsequent emissions tests.
Mobile Source Emission
Reduction Credits
A number of California's air quality
districts have instituted programs for
MSERCs. These credits apply to any vehi-
cle or engine that is converted to meet a
more stringent emissions standard (for
example TLEV to LEV) than the one to
which the vehicle was originally certified.
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California
Emission Certification Procedures
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Emission Certification Procedures
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Frequently Asked Questions
Here are answers to some commonly asked questions about emissions certification of aftermarket conversions.
Why are the costs of emissions certification so high?
EPA
Three components contribute to certification costs—fees, emission testing, and the labor associated with
organizing and processing the certification. The EPA does charge fees to provide the certification service.
Recognizing that the aftermarket vehicle conversion industry is still in its infancy, the EPA is currently looking
at methods to reduce or eliminate fees for certifying to certain emissions standards. The EPA also provides an
alternative method for determining fees. In regard to emissions testing, the EPA has attempted to reduce costs
for small volume manufacturers by providing alternative methods to derive DFs (for example, using EPA-
assigned DFs or using assigned DFs from an abbreviated durability test). You can minimize the time required
for organizing and processing of the certification by having a well-conceived plan and following the EPA's
directions for the information required on the application (see page 12).
California
In California, two components contribute to the certification costs—emissions testing and the labor associated
with organizing and processing the certification. California does not charge any fees for the certification service.
Recognizing that the durability portion of emissions testing poses a hardship on manufacturers, CARB has
developed alternative procedures for deriving DFs. CARB also stresses the need to have a well-conceived plan
and to follow its directions for the certification application.
Is the tank considered a part of the kit or aftermarket system for certification purposes?
EPA
By definition, the tank is an emissions control component. You should list it as a system component, and
describe it in the application. Holders of Certificates of Conformity must submit requests to the EPA for
approval to change the size, model, or number of tanks installed. For metal tanks, this is normally considered
a formality. However, if it is possible for fuel to permeate through the tank walls or fittings, the EPA is likely
to conduct a formal evaluation before granting any approval for changes.
California
You are not required to list the tank as a system component. However, you must list all hoses, because they are
possible sources of leaks that could affect evaporative emissions.
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Emission Certification Procedures
Questions
How long can vehicles be converted using the the EPA and California aftermarket certifications?
EPA
The EPA Certificate of Conformity has a finite life. Conversions can start on the effective date of the certificate
but must end no later than December 31 of the model year for which it is granted. The maximum period possi-
ble for conversions is one year and 364 days on that certificate (if the effective date was January 2 of the year
prior to the model year). To convert that same engine/vehicle past the December 31 date, you would have to
apply for a new certificate based on the standards and regulations that apply for the next model year (see
page 9).
California
You may start conversions on the approval date of the EO. The EO does not list an end date and you can con-
vert vehicles for however long engine families/vehicles are available to convert using that same EO.
Does the engine family name change as a result of aftermarket certification?
EPA
Yes, the engine family name changes to reflect the model year for which the certification is being granted
(if different from that of the original engine family) and the name of the company that has received the
certification. Also, three characters are reserved for your company's use (see page 9).
California
No, the engine family name stays the same.
Do CNG and LPG aftermarket conversions need to meet the same OBD regulations as
gasoline vehicles?
EPA
Yes, but you may request waivers from the federal OBD regulations. Providing you show technical justifica-
tion, the EPA may grant waivers, applicable to the alternative fuel portion only. The balance of the OBD system
must operate in compliance with the regulations. This waiver is available up to and including the 1998 model
year. The EPA has proposed to extend the waivers up to and including the 2004 model year (see page 23).
California
Yes, but you may request a waiver from complying with the OBD II regulations; this waiver is available up
to and including the 2004 model year. The aftermarket conversion system must still comply with California
OBD I regulations (see page 34).
Do manufacturers have to provide an emissions warranty as part of the certification
requirements for aftermarket conversions?
EPA
Yes, you are required to provide an emissions warranty. For light-duty vehicles and trucks, the warranty is in
two parts—an emissions performance warranty and an emissions design and defect warranty. Both are two
years or 24,000 miles, whichever comes first, and eight years or 80,000 miles, whichever comes first, for the
catalytic converter, the OBD device, and the electronic control unit. Heavy-duty engine manufacturers are
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Emission Certification Procedures
Questions
required to supply an emissions design and defect warranty of five years or 50,000 miles, whichever comes
first, for heavy-duty Otto-Cycle engines and light heavy-duty diesel engines, and five years or 100,000 miles,
whichever comes first, for all other heavy-duty engines. The warranty covers the labor to diagnose and repair
or replace the part, as well as any parts that need replacing. The emissions warranty period does not extend
beyond the emissions warranty that remained on the original vehicle prior to conversion (see page 24).
California
Yes, an emissions warranty is required. The same warranty applies to passenger cars, light-duty, medium-
duty, and heavy-duty vehicles. The warranty period is three years or 50,000 miles, whichever comes first, and
seven years or 70,000 miles, whichever comes first, for high-priced components. The warranty covers the labor
to diagnose and repair or replace the part as well as any parts that need replacing. The installer is also required
to supply a warranty that the installation was done correctly. The period of the warranty is three years or
50,000 miles, whichever comes first. The warranty is to cover the full repair of any damage resulting from an
incorrect installation. The warranty period for both the manufacturer and installer starts on the date of conver-
sion; the vehicle mileage at that time is considered to be zero (see page 34).
If I obtain an EPA emissions certification for a 50-state (or California-only) vehicle, do I still
need to obtain certification in California?
California requires that you apply for certification from CARB for vehicles that are to be used in California.
For a California-only vehicle, seek certification from CARB first, and then from the EPA. For a 50-state vehicle,
obtain EPA certification first, and then from CARB.
If I obtain a California aftermarket certification (an EO), will I be exempt from enforcement
actions under the Clean Air Act anti-tampering provisions?
In a September 4,1997 EPA policy document, addendum to Memorandum 1A "Tampering Enforcement Policy
for Alternative Fuel Aftermarket Conversions," the EPA clarifies the tampering enforcement policy and revises
the terms for establishing a reasonable basis that performing an aftermarket conversion will not adversely
affect emissions. If you follow one of the three options that are listed in the addendum, the EPA will not regard
the conversion as a violation of the anti-tampering provisions. One of those options is to certify according to
"California Certification and Installation Procedures for Alternative Fuel Retrofit Systems for Motor Vehicles
Certified for 1994 and Subsequent Model Years and for All Model Year Motor Vehicle Retrofit Systems
Certified for Emission Reduction Credit." This applies to a California-only engine family for use in California
only or a 50-state engine family for nationwide use. The EPA no longer accepts that the pre-1994 California
procedures provide an adequate demonstration that the aftermarket conversion will comply with the applica-
ble emission standards for the vehicle's useful life (see page 7).
When converting vehicles using Option 3 from the addendum to Memo 1A, do the FTP 75
results on the alternative fuel have to be better than those on gasoline?
No. The result that is to be compared to the emission standard must include the FTP test and the appropriately
applied DF. This overall result must then be compared to the standard for the model year of the vehicle or
engine being converted. All results must be within the standards for each of the regulated emissions through-
out the vehicle or engine's useful life.
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40
Emission Certification Procedures
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Emission Certification Procedures
r—»
Appendix A: Glossary of Terms
Abbreviations
AFV alternative fuel vehicle
ALVW adjusted loaded vehicle weight
APCD Air Pollution Control Division
(Colorado)
BAR Bureau of Automotive Repair
CAA Clean Air Act
CAFE corporate average fuel economy
CARB California Air Resources Board
CD Certification Division
CFF Clean-Fuel Fleet
CFFP Clean-Fuel Fleet Program
CFR Code of Federal Regulations
CFV clean-fuel vehicle
CNG compressed natural gas
CO carbon monoxide
CC>2 carbon dioxide
CPP California Pilot Program
DDV durability data vehicle
DF or DFs . . deterioration factor or factors
DOE U.S. Department of Energy
DOT U.S. Department of Transportation
EDV emissions data vehicle
EO Executive Order (California)
EPA U.S. Environmental Protection Agency
EPACT Energy Policy Act of 1992
FIP Federal Implementation Plan
FR Federal Register
FTP Federal Test Procedure
GVWR gross vehicle weight rating
HC hydrocarbons
HCHO formaldehyde
HDDE heavy-duty diesel engine (diesel-cycle)
HDE heavy-duty engine
HDGE heavy-duty gas engine (Otto-Cycle)
HDV heavy-duty vehicle
HHDDE . . . heavy heavy-duty diesel engine
(diesel-cycle)
HLDT heavy light-duty truck
HOV high-occupancy vehicle
ILEV inherently low-emission vehicle
IM inspection and maintenance
LDT light-duty truck
LDT1 light-duty truck 1
LDT2 light-duty truck 2
LDT3 light-duty truck 3
LDT4 light-duty truck 4
LDV light-duty vehicle
LEV low-emission vehicle
LHDDE .... light heavy-duty diesel engine
(diesel-cycle)
LLDT light light-duty truck
LNG liquefied natural gas
LPG liquefied petroleum gas
LVW loaded vehicle weight
MAC Manufacturers Advisory
Correspondence (California)
MDV medium-duty vehicle
MDV1 medium-duty vehicle 1
MDV2 medium-duty vehicle 2
MDV3 medium-duty vehicle 3
MDV4 medium-duty vehicle 4
MDV5 medium-duty vehicle 5
MERC Mobile Emissions Reduction Credit
(federal term)
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Appendix A
MHDDE
MSERC .
MY
NAAQS.
NMHC .
NMOG .
NOX . ...
NREL.
OBD....
OBD II. .
. medium heavy-duty diesel engine
(diesel-cycle)
. . Mobile Source Emissions Reduction
Credit (California term)
. model year
. . National Ambient Air Quality
Standards
. . non-methane hydrocarbons
. . non-methane organic gases
. . oxides of nitrogen
National Renewable Energy
Laboratory
. . on-board diagnostics
. . on-board diagnostics II
Emission Certification Procedures
OEM original equipment manufacturer
PC passenger car
PM particulate matter
QVM Qualified Vehicle Modifier
RAF reactivity adjustment factor
SIP State Implementation Plan
SULEV super-ultra-low-emission vehicle
THC total hydrocarbons
TLEV transitional low-emission vehicle
TW test weight
ULEV ultra low-emission vehicle
VIN vehicle identification number
ZEV zero-emission vehicle
Definitions
Adjusted loaded vehicle weight (ALVW): the numerical average of the curb weight and the GVWR.
Aftermarket conversion: a vehicle originally designed to operate on gasoline or diesel that has been modified
or altered to run on an alternative fuel. (See also 40 CFR Part 85.502(c).)
Alternative fuel: in the context of this guide, alternative fuel refers to CNG, LNG, and LPG.
Baseline emissions: emissions measured from relatively new vehicles or engines. Baseline emissions are
compared with emissions at higher mileage levels to determine DFs.
Bi-fuel vehicle (industry definition): a vehicle with two separate fuel systems designed to run on either an
alternative fuel, or gasoline or diesel, using only one fuel at a time. CARB defines bi-fuel differently,
which can create confusion.
Bi-fuel vehicle (CARB definition): a vehicle with two fuel systems (the conventional fuel and an alternative
fuel) capable of running on either the conventional fuel (gasoline or diesel) or both the conventional and
alternative fuel simultaneously.
Clean-fuel vehicle (CFV): any vehicle certified by the EPA as meeting CFV federal emissions standards.
The three categories of federal CFV standards from least to most stringent are LEV, ULEV, and ZEV. The
ILEV standard is voluntary and does not need to be adopted by states as part of the Clean-Fuel Fleet
Program (CFFP). CFVs are eligible for two federal programs, the California Pilot Program and the CFFP.
CFV exhaust emissions standards for light-duty vehicles and trucks are numerically similar to those of
California's Low-Emissions Vehicle Program.
Clean-Fuel Fleet Program (CFFP): a federal program that requires fleet purchase of CFVs beginning in model
year 1999.
Compressed natural gas (CNG): natural gas that has been compressed under high pressure. When used as
a motor vehicle fuel, it is stored in specially designed cylinders at pressures up to 3,600 pounds per
square inch (see also natural gas).
Conventional fuel: in the context of this guide, conventional fuel refers to gasoline or diesel.
Converted or conversion: (see aftermarket conversion)
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Emission Certification Procedures
Appendix A
Corporate Average Fuel Economy (CAFE): a program created to determine vehicle manufacturers'
compliance with the fuel economy standards set by the federal government. The Energy Policy and
Conservation Act, which passed in 1975, set the first federal fuel economy standards for light-duty
vehicles and trucks. The CAFE values are a weighted harmonic average of the EPA city and highway
fuel economy test results.
Conversion kit: equipment used to modify a vehicle originally designed to operate on gasoline or diesel that
has been modified or altered to run on an alternative fuel.
Curb weight: the manufacturer's estimated weight of the vehicle in operational status with all standard
equipment and weight of fuel at normal tank capacity, and the weight of optional equipment.
Dedicated alternative fuel vehicle: a vehicle that has been designed or modified to run on an alternative
fuel only.
Deterioration factor (DF): a numerical factor that is determined through various durability test procedures
and used to predict the increase in vehicle emissions caused by age or mileage accumulation. These
factors are applied to baseline emissions test results to determine compliance with useful life emissions
standards. Some are multiplied and others are added to the baseline emission results.
Diesel engine: any engine powered by diesel fuel or a gaseous fuel for which the diesel engine speed/torque
characteristics and vehicle applications are retained. (Commonly referred to as a compression-ignition
engine.)
Distributor: a company or individual that purchases aftermarket conversion equipment or kits for the purpose
of reselling to other companies or individuals, such as an installer, without installing the conversion kit.
Dual-fuel vehicle (CAA/EPA/CARB definition): a vehicle with two separate fuel systems designed to run on
either an alternative fuel or conventional gasoline, using only one fuel at a time. We use this definition for
dual-fuel in this guide. (See also 40 CFR Part 88.102-94.)
Dual-fuel vehicle (industry/EPACT definition): a vehicle designed to operate on a combination of an alterna-
tive fuel and a conventional fuel, including: (1) vehicles using a mixture of gasoline or diesel and an alter-
native fuel in one fuel tank, commonly called flexible-fuel vehicles; and (2) vehicles capable of operating
either on an alternative fuel, a conventional fuel, or both, simultaneously using two fuel systems.
Durability: a vehicle's or engine's ability to maintain a given emissions level over its useful life. Durability
tests are performed by manufacturers to predict the emissions deterioration rate with increased mileage
(see also DFs and useful life).
Durability data vehicle (DDV): a vehicle used to test for deterioration of emissions over a period of use.
The test results are used to determine DFs.
Emissions data vehicle (EDV): a vehicle used to test for baseline emissions. DFs are applied to the baseline
emissions results to determine compliance with useful life emissions standards.
Engine family: the EPA and CARB define engine family as a group of engines with the same emissions
characteristics throughout their useful life. The engines must be identical in a number of respects such
as cylinder bore center-to-center dimensions, cylinder block configuration, location of the intake and
exhaust valves, method of air inspiration, combustion cycle, and catalytic converter characteristics.
Evaporative emissions: hydrocarbon vapors that escape from a fuel storage tank, a vehicle fuel tank, or a
vehicle fuel system.
Full useful life: (see useful life)
Gross vehicle weight rating (GVWR): maximum loaded weight for which the vehicle is designed, as
specified by the vehicle manufacturer.
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Emission Certification Procedures
Appendix A
Heavy-duty engine: a diesel or an Otto-Cycle engine that powers a heavy-duty vehicle. The EPA designation
for a heavy-duty vehicle is any vehicle above 8,500 pounds GVWR; the CARD designation is for any
vehicle above 6,000 pounds GVWR. Exhaust emission testing is carried out on a engine dynamometer.
Heavy-duty vehicle: (see heavy-duty engine)
Inherently low-emission vehicle (ILEV): a vehicle meeting EPA's CFV ILEV standards (federal only—see
Appendix D). Evaporative emissions must be 5 grams or less per test without using any and all auxiliary
emission control devices. In most cases, ILEVs will be dedicated AFVs. Dual-fuel vehicles will be consid-
ered ILEVs only if both fuels meet the standard. ILEVs may be exempt from certain transportation control
measures, including HOV lane restrictions. This standard is voluntary and need not be adopted by states.
Installer: any company or individual that installs an aftermarket conversion system on a vehicle or engine.
(See also 40 CFR Part 85.502(d).)
Intermediate useful life: (see useful life)
Light-duty truck (LDT): there are a number of different vehicle weight categories within the light-duty truck
vehicle designation. The EPA designation for light-duty truck is any truck with a GVWR of 8,500 pounds
or less and a curb weight of 6,000 pounds or less; the CARB designation applies to any truck with a
GVWR of less than 6,000 pounds.
Light-duty vehicle (LDV): an EPA term that means a passenger car or passenger-car derivative capable of
seating 12 or fewer passengers (see also passenger car).
Liquefied natural gas (LNG): natural gas that has been condensed to a liquid—typically, by cryogenically
cooling the gas (see also natural gas).
Liquefied petroleum gas (LPG): also known as propane, a mixture of hydrocarbons found in natural gas and
also produced from crude oil. In addition to its use as a vehicle fuel, it is used principally as a feedstock
for the chemical industry, a home heating fuel, and a motor vehicle fuel. When used as a motor vehicle
fuel, the primary component of LPG is propane.
Loaded vehicle weight (LVW): a vehicle's curb weight plus 300 pounds.
Low-emission vehicle (LEV): a vehicle that meets either the EPA's CFV LEV standards or California's Low-
Emission Vehicle Program standards (see Appendix D). LEVs produce fewer emissions than TLEVs.
Medium-duty vehicle (MDV): CARB term that means any pre-1995 model year heavy-duty vehicle having
a GVWR of 8,500 pounds or less; any 1992 and subsequent model year heavy-duty LEV, ULEV, SULEV,
or ZEV having a GVWR of 14,000 pounds or less; or any 1995 and subsequent model year heavy-duty
vehicle having a GVWR of 14,000 pounds or less. Exhaust emissions testing of MDVs is performed on a
chassis dynamometer.
Model year: an OEM's annual production period. Further, a specific model year must include January 1 of
that calendar year and not include January 1 of any other calendar year. The maximum duration of the
model year is one calendar year plus 364 days. (See also 40 CFR Part 85.2302 and 85.2303.)
Natural gas: a mixture of gaseous hydrocarbons, primarily methane, which occurs naturally in the earth and
is used principally as a fuel.
Non-methane organic gas (NMOG): the sum of non-oxygenated and oxygenated hydrocarbons contained in
a gas sample as measured in accordance with California's test procedures. With vehicles using fuels other
than gasoline, the level of NMOG emissions is adjusted based on the reactivity of the emissions relative to
vehicles using gasoline.
Nonattainment area: a region, determined by population density in accordance with the U.S. Census Bureau,
which exceeds minimum acceptable National Ambient Air Quality Standards (NAAQS) for one or more
"criteria pollutants." Such areas are required to seek modifications to their State Implementation Plans,
-------
Emission Certification Procedures
Appendix A
setting forth a reasonable timetable for meeting NAAQS using EPA-approved means. Under the CAA, if
a nonattainment area fails to meet NAAQS, the EPA may impose a Federal Implementation Plan with
stricter requirements, or impose fines, construction bans, or cutoffs in federal grant revenues, until the
area achieves the applicable NAAQS.
Office of Mobile Sources: a division of the EPA that proposes, promulgates, and enforces regulations to con-
trol emissions from motor fuels, vehicles, motor vehicle engines, and non-road engines.
On-board diagnostics system (OBD system): a system made up of sensors, actuators, the OBD computer
(which is usually the same as the electronic control unit that controls other engine functions) and its soft-
ware, and interconnecting cables and wires. Its purpose is to ensure proper emission control system oper-
ation for the useful life of the vehicle by monitoring emissions-related components and systems for
deterioration and malfunction.
On-board refueling vapor recovery (ORVR): a system required on vehicles beginning in 1998 to recover
hydrocarbon vapors that escape during refueling.
Otto-Cycle engine: any engine in which the primary means of controlling power output is by limiting the
amount of air and fuel that can enter the combustion chambers of the engine (commonly referred to as a
spark-ignited engine).
Passenger car (PC): CARB term meaning any motor vehicle designed primarily for transportation of persons
and having a design capacity of 12 or fewer persons (see also light-duty vehicle).
Reactivity adjustment factor (RAF): numerical multipliers used in the certification of vehicles to the
California emissions standards to reflect reduced ozone-forming potential of emissions from various
fuels, especially alternative fuels.
Retrofit: (see aftermarket conversion)
Super-ultra-low-emission vehicle (SULEV): an MDV in California that produces fewer emissions than a
ULEV vehicle (see Appendix D). Because there is no federal equivalent, such a vehicle qualifies as a
ULEV vehicle under the CFFP.
Tier 0: federal emissions standards for LDVs and trucks prior to the tier 1 phase (see Appendix D).
Tier 1: more stringent federal emissions standards for LDVs and LDTs phased in beginning in MY 1994 and
required for all 1996 model year light-duty vehicles and trucks (see Appendix D).
Transitional low-emission vehicle (TLEV): a vehicle that meets either the EPA's TLEV standards or
California's Low-Emissions Vehicle Program TLEV standards (see Appendix D). TLEVs produce fewer
emissions than federal tier 1 vehicles. TLEVs are eligible for the federal California Pilot Program but are
not eligible for the federal CFFP.
Ultra low-emission vehicle (ULEV): a vehicle that meets either the EPA's CFV ULEV standards or
California's Low-Emission Vehicle Program ULEV standards (see Appendix D). ULEVs produce fewer
emissions than LEVs. Fleets that purchase CFV ULEVs may earn credits under the CFFV Program.
Manufacturers that sell CFV ULEVs may earn credits under the federal California Pilot Program.
Useful life: a period of vehicle or engine use expressed in years or miles defining the emissions standards to
which a vehicle or engine is being certified. Vehicles or engines are certified to meet emissions standards
that are projected out to their intermediate or full useful life (such as five years or 50,000 miles, whichever
comes first; ten years or 100,000 miles, whichever comes first, etc.). Baseline emissions tests are performed
and DFs are applied to determine if the vehicle will meet the standards defined for a given useful life.
Zero-emission vehicle (ZEV): a vehicle that meets either the EPA's CFV ZEV standards or CARB's California
Low-Emission Vehicle ZEV standards. ZEV standards, usually met with electric vehicles, do not permit
any exhaust emissions of the regulated pollutants or evaporative emissions during vehicle use.
-------
Appendix B: Schematics of Commercial Aftermarket Conversion Systems
This appendix contains schematics of two commercially available aftermarket conversion kits.
Example of a CNG Conversion System
Tank Valves
Regulator
Single Stage
Pressure Regulator
Fuel
Selector
Switch
Manually
Operated
Solenoid
Operated
Fuse and Relay Module
To Engine
Coolant Circuit
Multi-Point
( Injection
Engine Sensor
Input and Output
Compuvalve
Combined Computer
and Metering Valve
Schematic Courtesy of GFI Control Systems, Inc.
-------
Example of an LPG Conversion System
3-way idle bypass trim valve
Ambient
pressure signal
10 NfTl 3-way fuel control valve
Remote Remote Remote
discharge fill valve fixed level
OEM A/F sensor
Fuel Lockoff
Converter/Regulator
Fuel level
sender
Propane Tank
OEM air cleaner
Engine
coolant/
Heater lines
Manual service valve/
Hydrostatic relief valve
Air valve/ ,
gas valve mixer
Intake solenoid
with excess
flow valve
J OEM A/F signal
Engine rpm signal (CKP sensor
Oxygen sensor signal
Schematic Courtesy of IMPCO Technologies, Inc.
-------
Appendix C
Appendix C: Informative Web Sites
Certification and Regulations
U.S. Government Printing Office
Code of Federal Regulations and Federal Register http://www.access.gpo.gov/nara/index.html
U.S. Environmental Protection Agency
Office of Mobile Sources http://www.epa.gov/omswww
Clean Air Act Regulations http://www.epa.gov/oar/caa/contents.html
Clean Fuel Fleets http://www.epa.gov/omswww/cff.htm
Small Volume Manufacturers Application —
for Certificate of Conformity. http://www.epa.gov/omswww/gopher/Cert/
Dearmfr/gasappx5.pdf (or Igasappx5.txt)
Standardized Engine and
Evaporative Family Names http://www.epa.gov/omswww/gopher/Cert/
CFEIS/cmug-f.pdf
California Air Resources Board http://www.arb.ca.gov
Colorado Department of Public Health
and Environment http://www.state.co.us/gov_dir/cdphe_dir
General Alternative Fuels Information
U.S. Department of Energy
Office of Transportation Technologies http://www.ott.doe.gov
Clean Cities http://www.ccities.doe.gov
Alternative Fuels Data Center http://www.afdc.doe.gov
-------
Appendix D: Emissions Standards
Summary of Federal and California Exhaust Emissions
Standards for CNG, LPG, Gasoline, and Diesel1
This table summarizes exhaust emissions standards. Although it does not
cover all the exhaust standards, it does provide information on those that we
have mentioned frequently. See Tables 3,4, and 11 in the body of the guide for
sources of information for other details on exhaust, evaporative, and other
emissions standards. See Appendix A for an explanation of all abbreviations.
Vehicle
GVWR in
Pounds
0-6,000
Weight in
Pounds
0-3,750
LVW
3751-
5750
LVW
Type
Light-Duty
Vehicle
Passenger Car
Light-Duty
Truck 1
Light-Duty
Truck 2
Emissions
Category3
Fed tier 0
Fed tier 1
Fed LEV
Fed ILEV
Fed ULEV
Ca tier 0
CA tier 1
CA TLEV
CA LEV
CA ULEV
Fed tier 0
Fed tier 1
Fed LEV
Fed ILEV
Fed ULEV
CA tier 0
CA tier 1
CA TLEV
CA LEV
CA ULEV
Fed tier 0
Fed tier 1
Fed LEV
Fed ILEV
Fed ULEV
CA tier 0
CA tier 1
CA TLEV
CALEV
CA ULEV
Exhaust Emissions Standards, in grams per mile
50,000 Miles
THCb
0.41
0.41
(NMHC)C
NMOG"
(0.34)f
(0.25)
0.075
0.075
0.040
(0.39)
(0.25)
0.125
0.075
0.040
(0.25)
0.075
0.075
0.040
(0.39)
(0.25)
0.125
0.075
0.04
(0.32)
0.100
0.100
0.050
(0.50)
(0.32)
0.160
0.100
0.050
CO
3.4
3.4
3.4
3.4
1.7
7.0
3.4
3.4
3.4
1.7
3.4
3.4
3.4
1.7
9.0
3.4
3.4
3.4
1.7
4.4
4.4
4.4
2.2
9.0
4.4
4.4
4.4
2.2
NOX
1.0
0.4
0.2
0.2
0.2
0.4
0.4
0.4
0.2
0.2
0.4
0.2
0.2
0.2
0.4
0.4
0.4
0.2
0.2
0.7
0.4
0.4
0.4
1.0
0.7
0.7
0.4
0.4
HCHO
0.015
0.015
0.008
0.015
0.015
0.008
0.015
0.015
0.008
0.015
0.015
0.008
0.018
0.018
0.009
0.018
0.018
0.009
PMe
0.20
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
100,000 Miles
(NMHC)C
NMOG"
(0.31)
0.090
0.090
0.055
(0.31)
0.156
0.090
0.055
(0.31)
0.090
0.090
0.055
(0.31)
0.156
0.090
0.055
(0.40)
0.130
0.130
0.070
(0.40)
0.200
0.130
0.070
CO
4.2
4.2
4.2
2.1
4.2
4.2
4.2
2.1
4.2
4.2
4.2
2.1
4.2
4.2
4.2
2.1
5.5
5.5
5.5
2.8
5.5
5.5
5.5
2.8
NOX
0.6
0.3
0.3
0.3
0.6
0.6
0.3
0.3
0.6
0.3
0.3
0.3
0.6
0.6
0.3
0.3
0.97
0.5
0.5
0.5
0.97
0.9
0.5
0.5
HCHO
0.018
0.018
0.011
0.018
0.018
0.011
0.018
0.018
0.011
0.018
0.018
0.011
0.023
0.023
0.013
0.023
0.023
0.013
PMe
0.10
0.08
0.08
0.04
0.08
0.08
0.04
0.10
0.08
0.08
0.04
0.08
0.08
0.04
0.10
0.08
0.08
0.04
0.10
0.10
0.05
120,000 Miles
THCb
0.80
0.80
0.80
0.80
(NMHC)C
NMOGd
(0.67)f
(0.67)f
CO
10
2.1
10
NOX
1.2
1.7
HCHO
0.055
PMe
0.26
0.13
<*>
T*t.
o
s
n
-------
Vehicle
GVWR in
Pounds
6,001-
8,500
8,501-
14,000
Weight in
Pounds
0-3,750
LVW
3,751-
5,750 LVW
5,751-
8,500 LVW
0-3,750
A LVW
3,751-
5,750
A LVW
5,751-
8,500
ALVW
8,501-
10,000
ALVW
m nm
14,000
ALVW
Type
Heavy Light-Duty Truck
Medium-Duty Vehicle
Heavy Light-Duty Truck
Medium-Duty Vehicle
Heavy Light-Duty Truck
Medium-Duty Vehicle
Heavy Light-Duty
Truck
Medium-Duty
Vehicle 1
Light-Duty
Truck 3
Medium-Duty
Vehicle 2
Light-Duty
Truck 4
Medium-Duty
Vehicle 3
Medium-Duty
Vehicle 4
Medium-Duty
Vehicle 5
Emissions
Category3
Fed tier 0
CA tier 0
Fed tier 0
CA tier 0
Fed tier 0
CA tier 0
Fed LEV
Fed ILEV
Fed ULEV
CA tier 1
CALEV
CA ULEV
Fed tier 1
Fed LEV
Fed ILEV
Fed ULEV
CA tier 1
CALEV
CA ULEV
CA SULEV
Fed tier 1
Fed LEV
Fed ILEV
Fed ULEV
CA tier 1
CALEV
CA ULEV
CA SULEV
CA tier 1
CALEV
CA ULEV
CA SULEV
CA tier 1
CALEV
CA ULEV
CA SULEV
Exhaust Emissions Standards, in grams per mile
50,000 Miles
THC"
(NMHC)C
NMOGd
(0.39)
(0.50)
(0.60)
0.125
0.125
0.075
(0.25)
0.125
0.075
(0.32)
0.160
0.160
0.100
(0.32)
0.160
0.100
0.050
(0.39)
0.195
0.195
0.117
(0.39)
0.195
0.117
0.059
(0.46)
0.230
0.138
0.069
(0.60)
0.300
0.180
0.090
CO
9.0
9.0
9.0
3.4
3.4
1.7
3.4
3.4
1.7
4.4
4.4
4.4
2.2
4.4
4.4
4.4
2.2
5.0
5.0
5.0
2.5
5.0
5.0
5.0
2.5
5.5
5.5
5.5
2.8
7.0
7.0
7.0
3.5
NOX
0.4
1.0
1.5
0.4
0.2
0.2
0.4
0.4
0.2
0.7
0.7
0.4
0.4
0.7
0.49
0.4
0.2
1.1
1.1
0.6
0.6
1.1
0.61'
0.6
0.3
1.3
0.7k
0.7
0.35
2.0
1.0m
1.0
0.5
HCHO
0.015
0.015
0.008
0.015
0.008
0.018
0.018
0.009
0.018
0.009
0.004
0.022
0.022
0.011
0.022
0.011
0.006
0.028
0.014
0.007
0.036
0.018
0.090
PMe
0.08
0.08
0.08
100,000 Miles
(NMHC)C
NMOG"
CO
NOX
HCHO
PMe
120,000 Miles
THCb
0.80
0.80
0.80
0.80
0.80
(NMHC)C
NMOGd
(0.67)f
(0.67)f
(0.67)f
0.180
0.180
0.107
(0.36)
0.180
0.107
(0.46)
0.230
0.230
0.143
(0.46)
0.230
0.143
0.072
(0.56)
0.280
0.280
0.167
(0.56)
0.280
0.167
0.084
(0.66)
0.330
0.197
0.100
(0.86)
0.430
0.257
0.130
CO
10
10
10
5.0
5.0
2.5
5.0
5.0
2.5
6.4
6.4
6.4
3.2
6.4
6.4
6.4
3.2
7.3
7.3
7.3
3.7
7.3
7.3
7.3
3.7
8.1
8.1
8.1
4.1
10.3
10.3
10.3
5.2
NOX
1.2
1.7
1.7
0.6
0.3
0.3
0.55
0.6
0.3
0.98
1.0
0.5
0.5
0.98
0.6h
0.6
0.3
1.53
1.5
0.8
0.8
1.53
0.9j
0.9
0.45
1.81
1.01
1.0
0.5
2.77
1.5"
1.5
0.7
HCHO
0.022
0.022
0.012
0.022
0.012
0.027
0.027
0.013
0.027
0.013
0.006
0.032
0.032
0.016
0.032
0.016
0.008
0.040
0.021
0.010
0.052
0.026
0.013
PMe
0.26
0.13
0.13
0.08
0.08
0.04
0.08
0.08
0.04
0.10
0.10
0.10
0.05
0.10
0.10
0.05
0.05
0.12
0.12
0.12
0.06
0.12
0.12
0.06
0.06
0.12
0.12
0.06
0.06
0.12
0.12
0.06
0.06
-------
Vehicle
GVWR in
Pounds
8,501-
14,000
8,501-
14,000
Greater Than
14,000
Greater Than
8,501X
Weight in
Pounds
Type
Medium-Duty
Vehicle (OPT)0
8,501-14,000 GVWR
Heavy-Duty
Otto-Cycle Engine5'*
Heavy-Duty
Otto-Cycle Engine5'1
Heavy-Duty
Diesel Engines'y
Heavy-Duty Otto-Cycle
and Diesel EngineSit-y
Emissions
Category3
CA tier 1
CALEV
CA ULEV
Fed
Fed & CA
Fed & CA
Fed LEV
Fed ILEV
Fed ULEV
Exhaust Emissions Standards, in grams per mile
50,000 Miles
THC"
(NMHC)C
NMOGd
CO
NOX
HCHO
PMe
100,000 Miles
(NMHC)C
NMOGd
CO
NOX
HCHO
PMe
120,000 Miles
THCb
1.1
1.9
1.3
1.3Z
1.3Z
1.3Z
(NMHC)C
NMOGd
(3.9)"
(3.5)"
(2.5)"
(0.9)f
(1.7)'
(1.2)"
(3.8)"
(2.5)p
(2-5)p
CO
14.4
14.4
14.4q
14.4
37.1
15.5
15.5aa
14.4
7.2
NOX
4.0U
4.0W
4.0W
4.0"
4.0"
4.0U
HCHO
0.050
0.050r
0.05
0.025
PMe
0.10
0.10
0.05
0.10
0.10
0.10
0.05
Cfi
V)
r4.
o
s
r>
S>
'-+•
*•*.
O
s
I
n
1 Diesel standards are provided for HDEs only.
a "Fed" means federal; "CA" means California
b CNG is exempt from THC standard.
c NMHC standards are within parentheses.
d Dual-fuel PCs, LDVs, LDTs, and MDVs that are a part of federal LEV and
ULEV and California TLEV, LEV, ULEV, & SULEV emission categories may
have different NMOG standards than those listed in this table. Gasoline is
required to meet the standards for the emissions category for the original MY
and a new gasoline NMOG standard. Refer to the next table for the NMOG
standards if different than above.
e Shaded PM standards in this column refer to diesel only standard.
f NMHC standard applies to CNG only.
s Prior to MY 1998, the standard is 0.7.
h Prior to MY 1998, the standard is 1.0.
1 Prior to MY 1998, the standard is 1.1.
i Prior to MY 1998, the standard is 1.5.
k Prior to MY 1998, the standard is 1.3.
1 Prior to MY 1998, the standard is 1.8.
m Prior to MY 1998, the standard is 2.0.
n Prior to MY 1998, the standard is 2.8.
0 Optional standard for incomplete medium-duty vehicles of 8,501-14,000 Ib
GVWR. Emissions standards are in grams per brake horsepower-hour.
P Combined NMHC and NOX standard.
14.4 grams per brake horsepower-hour for Otto-Cycle and 7.2 for
diesel-cycle.
0.050 applies to Otto-Cycle engines. For diesel-cycle engines, the
standard is 0.025.
Standards are in grams per brake horsepower-hour.
Useful life is eight years or 110,000 miles for heavy-duty Otto-Cycle engines.
Prior to MY 1998, the standard is 5.0. CNG remains at 5.0 for MY 1998.
In MY 1998, the year portion of useful life becomes ten years.
Optional for California. For federal, applies to CNG only.
Prior to MY 1998, the standard is 5.0. In MY 1998, CNG remains
at 5.0 for federal certification and changes to 4.0 for California certification. In
MY 1998 the year portion of useful life becomes ten years.
California vehicle weight category is greater than 14,000 Ib GVWR.
Useful life is eight years or 110,000 miles for LHDDE, 185,000 miles for
MHDDE, and 290,000 miles for HHDDE.
1.3 grams per brake horsepower-hour for diesel-cycle, 1.1 for Otto-Cycle
engines in vehicles weighing 14,000 Ib or less GVWR, and 1.9 for Otto-Cycle
engines in vehicles weighing more than 14,000 Ib GVWR.
a!5.5 grams per brake horsepower-hour for diesel-cycle, 14.4 for Otto-Cycle
engines in vehicles weighing 14,000 Ib or less GVWR, and 37.1 for Otto-Cycle
engines in vehicles weighing more than 14,000 Ib.
-------
Emission Certification Procedures
Appendix D
Appendix D - Emission Standards (concluded):
Additional NMOG Standards3 for Dual-Fuel Vehicles, in grams per mile
In order to certify a dual-fuel vehicle to a TLEV, LEV, ULEV, or SULEV emissions standard, emissions on both
CNG and LPG must comply with the standards specified in the previous table with the exception of those
NMOG standards listed here. Gasoline emissions are not to exceed the standards applicable to the original
model year of the vehicle, and the NMOG standards given here. See Appendix A for an explanation of all
abbreviations.
Vehicle Type
Light-Duty Vehicle,
Passenger Car,
Light- Duty Truck 1
(0-3750 Ib LVW)
Light-Duty Truck 2
(3751-5750 Ib LVW)
Heavy Light-Duty Truck,
Medium-Duty Vehicle 1
(0-3750 Ib ALVW)
Light-Duty Truck 3,
Medium-Duty Vehicle 2
(3751 5750 Ib ALVW)
Light-Duty Truck 4,
Medium-Duty Vehicle 3
(5751-8500 Ib ALVW)
Medium-Duty Vehicle 4
(8501 10 000 Ib ALVW)
Medium-Duty Vehicle 5
(10,001-14,000 Ib ALVW)
Emissions
Category13
Fed All
CA TLEV
CA LEV
CA ULEV
Fed All
CA TLEV
CA LEV
CA ULEV
Fed All
CA LEV
CA ULEV
Fed All
CA LEV
CA ULEV
CA SULEV
Fed All
CA LEV
CA ULEV
CA SULEV
CALEV
CA ULEV
CA SULEV
CA LEV
CA ULEV
CA SULEV
NMOG Standards, in grams per mile
50,000 Miles
CNG
or LPG
0.125
0.160
0.125
0.160
0.195
Gasoline
0.25
0.25
0.125
0.075
0.32
0.32
0.160
0.100
0.25
0.25
0.125
0.32
0.32
0.160
0.100
0.39
0.39
0.195
0.117
0.46
0.230
0.138
0.60
0.300
0.180
100,000 Miles
CNG
or LPG
0.156
0.200
0.180
0.230
0.280
Gasoline
0.31
0.31
0.156
0.090
0.40
0.40
0.200
0.130
0.36
0.36
0.180
0.46
0.46
0.230
0.143
0.56
0.56
0.280
0.167
0.66
0.330
0.197
0.86
0.430
0.257
a Applies to federal CFV and California TLEV, LEV, ULEV, and SULEV emissions categories.
b "Fed" means federal; "CA" means California
-------
Emission Certification Procedures
Appendix E
Appendix E - Fuel Specifications for Emissions
Certification Purposes
EPA - Natural Gas Certification (Test) Fuel for Exhaust and Evaporative Emission Testing
Constituent
Methane
Ethane
C3 and higher
C6 and higher
Oxygen
Inert Gases
Odorant
Certification Test Fuel for Exhaust
and Evaporative Emission Testing3
Minimum of 89.0
Maximum of 4.5
Maximum of 2.3
Maximum of 0.2
Maximum of 0.6
Maximum of 4.0
The natural gas at ambient conditions must have a
distinctive odor potent enough for its presence to
be detected down to a concentration in air of not
over one-fifth of the Lower Limit of fLammabiLity.
All units are in
mole percent
California - Natural Gas Certification (Test) Fuel and Commercial Fuel
Constituent
Methane
Ethane
C3 and higher
Oxygen
Inert Gases
Certification Test Fuel for Exhaust
and Evaporative Emission Testing3
90.0% + 1%
4.0% ± 0.5%
2.0% ± 0.3%
maximum of 0.5%
3.5% ± 0.5%
Commercial Fuel for
Mileage Accumulation3
Minimum of 88.0%
Maximum of 6.0%
Maximum of 3.0%
Maximum of 1.0%
1.5% to 4.5%
All units are in
mole percent
California - Liquefied Petroleum Gas Certification (Test) Fuel and Commercial Fuel
Constituent
Propane
Butane and heavier
Propene
Certification Test Fuel for Exhaust
and Evaporative Emission Testing
93.5% ± 1.0 % by voLume
1.9% ± 0.3% by voLume
3.8% + 0.5% by voLume
Commercial Fuel for
Mileage Accumulation
Minimum of 85.0% by voLume
Maximum of 2.5% by voLume
Maximum of 5.0% by voLume
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Appendix F
54
Emission Certification Procedures
Submit plan for use of gasoline DFs
No / CARB
approval
Appendix F:
California Certification Process
for Aftermarket Conversions-
Use of Gasoline
Deterioration Factors
Acquire the following data at 4,000 miles on gasoline and on
alternative fuel, and at the useful life mileage level on alternative fuel only:
1) emissions
2) catalyst temperatures
3) air/fuel calibration
Demonstrate that the alternative fuel calibation is similar to gasoline,
and that catalyst thermal degradation is not increased relative to gasoline
No / CARB
approval
One time
demonstration to
qualify for use of
gasoline DFs
t
Acquire 4,000 mile data on the EDV
1
t
Certification using
gasoline DFs
Demonstrate equivalent calibration control and similar catalyst temperatures.
Apply gasoline DFs to 4,000 mile data to determine useful life emissions
o
Manufacturer
Action
OCARB
Action
Submit application for certification
Insufficient information
Abbreviations
CARB California Air Resources
Board
DF Deterioration Factor
EDV Emissions Data Vehicle
Issue Executive Order
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Emission Certification Procedures
Appendix G:
California Certification Process
for Aftermarket Conversions-
Using Carry-Over and
Carry-Across of Deterioration
Factors
Submit certification plan for EFs
Establish durability on the demonstration DDV
These are
prerequisites
for using
MAC 95-05
t
Submit carry-over and carry-across plan if not
submitted previously with certification plan
The provisions
of MAC 95-05
are applicable
CRITERIA
1) Similar kit (same hardware
and different calibration)
2) EF has less stringent
standards to meet
3) EF contains a DDV in
same grouping as the
demonstration DDV
CARB review of carry-over/carry-across plan
Does
EF contain
the same OEM DDV as the
demonstration
DDV?
No .s Same kit
as demonstration
DDV?
Carry-over and carry-across
of DFs cannot be used
Obtain 4,000 mile emissions test
results and CAT temperature data
on the EDV from the EF in question
Conduct 4,000 mile emissions test
Review compliance with
criteria and CAT temperature data
Abbreviations
CARB California Air Resources Board
CAT Catalytic Converter
DDV Durability Data Vehicle
EDV Emissions Data Vehicle
EF Engine Family
MAC Manufacturers Advisory
Correspondence
OEM Original Equipment
Manufacturer
Are
CAT temperatures
acceptable?
Apply durability data from the
demonstration DDV to
determine useful life emissions
Submit complete
certification application
Insufficient
information
o
Manufacturer
Action
CARB
Action
CARB
approves application
-------
Appendix H
56
Emission Certification Procedures
Appendix H:
California Certification Process
for Light- and Medium-Duty
Aftermarket Conversions-
Using Derived Deterioration Factors
Obtain emissions data. Compare the results to
the standards after accumulation of 4,000 miles
Submit data, warranty, installation
instructions, label, durability testing plan, etc.
CARB validates
compliance with OBD
requirements
CARB
approves certification
information
CARB issues EO
Accumulate mileage
Abbreviations
Submit year 1 validation report
Conduct emissions tests at 100,000 and 120,000 miles
Submit validation data
CARB reviews data
Remediate,
with CARB approval
Are manufacturer
DFs validated?
EO remains in effect
CARB California Air Resources Board
DF Deterioration Factor
EO Executive Order
OBD On-Board Diagnostics
Manufacturer
Action
CARB
Action
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Emission Certification Procedures
57
Appendix I
Appendix I:
California Certification Process for
Heavy-Duty Aftermarket Conversions-
Using Derived Deterioration Factors
Submit intent/plan to use MAC 95-07
1) Make performance comparison
2) Demonstrate component durability
3) Conduct certification test after 100 hours
and apply manufacturer-derived DFs to
determine useful life emissions
4) Submit validation plan
Submit required certification information
O
Manufacturer
Action
CARB
Action
Abbreviations
CARB California Air Resources Board
DF Deterioration Factor
EO Executive Order
MAC Manufacturers Advisory
Correspondence
CARB
approves certification
information
Accumulate hours on engine
(submit progress report after one year)
Test at 1,000 hours and
project emissions to useful life
Remediate,
with CARB approval
Are manufacturer
DFs validated?
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58
Emission Certification Procedures
Appendix J
Appendix J: Contacts
Government Certification Organizations
EPA Light-Duty Vehicles and Trucks
Environmental Protection Agency
Office of Mobile Sources
Vehicle Programs and Compliance Division
Vehicle Programs Group
2565 Plymouth Road
Ann Arbor, MI 48105
EPA Alternative Fuels Hotline
Telephone: (734) 668-4312
Fax: (734) 741-7869
**New Hotline numbers as of May 1998
Telephone: (734) 214-4312
Fax: (734) 214-4869
EPA Heavy-Duty Engines
Environmental Protection Agency
Office of Mobile Sources
Engine Compliance Programs Group
Mailing Address: 401 M St. S.W. (6403J)
Washington, DC 20460
Visiting Location and Courier Shipments:
501 3rd St. N.W.
Washington, DC 20001
Telephone: (202) 564-9261
Fax: (202) 565-2057
California
California Environmental Protection Agency
Air Resources Board
Mobile Source Operations Division
Aftermarket Parts Section
9528 Telstar Avenue
P.O. Box 8001
El Monte, CA 91731
Telephone: (818) 575-6800
Fax: (818) 575-6685
Colorado
Colorado Department of Public Health
and Environment
APCD-MSP-B1
4300 Cherry Creek Drive South
Denver, CO 80222
Telephone: (303) 692-3125
Fax: (303) 782-5693
Information about EPA Memorandum 1A or
the Addendum to Memorandum 1A
Environmental Protection Agency
Office of Enforcement and Compliance Assurance
Mobile Source Enforcement Branch
Washington, DC 20460
Telephone: (202) 564-2255
Ordering Information for Code of Federal
Regulations or Federal Register
U.S. Government Printing Office
Superintendent of Documents
P.O. Box 371954
Pittsburgh, PA 15250-7954
Telephone: (202) 512-1800
Fax: (202) 512-2250
DOE National Alternative Fuels Hotline
Department of Energy
Office of Transportation Technologies
National Alternative Fuels Hotline
9300 Lee Highway
Fairfax, VA 22031
Telephone:
Fax:
(800) 423-1363
(703) 934-3183
Industry Organizations
The Natural Gas Vehicle Coalition
1515 Wilson Boulevard
Suite 1030
Arlington, VA 22209
Telephone: (703) 527-3022
Fax: (703) 527-3025
Propane Vehicle Council
1101 17th Street, N.W.
Suite 1004
Washington, DC 20036
Telephone: (202) 530-0479
Fax: (202) 466-7205
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Emission Certification Procedures
59
Appendix K
Appendix K: Important Documents
The documents listed in this appendix are available from the organization listed in the source column of the
table. Many of the EPA and Government Printing Office documents can be downloaded from either the EPA
Office of Mobile Sources or the U.S. Government Printing Office (Code of Federal Regulations and Federal Register)
Web sites, which are provided in Appendix C. Mailing and telephone information is provided in Appendix J.
Refer to Appendix A for an explanation of abbreviations.
Title or Description
Addendum to Mobile Source Enforcement Memorandum 1A,
"Tampering Enforcement Policy for Alternative Fuel
Aftermarket Conversions"
Certification and Fuel Economy Information System Manufacturer
User Guide, Appendix F, "EPA Standardized Engine and
Evaporative Family Names"
EPA Small Volume Manufacturers Application Letter and Package
Fact Sheet - "Certification and Fuel Economy Guidelines Small
Volume Light-Duty Vehicle and Light-Duty Truck Manufacturers"
"Mobile Source Emission Standards Summary"
QMS Advisory Circular A/C No. 17F, "General Criteria for the
Carryover and Carry- Across of Certification Data and the
Carryover of Fuel Economy Data for Light-Duty Vehicles and
Light-Duty Trucks"
MSAPC Advisory Circular A/C No. 37- A,
"Alternative Mileage Accumulation Procedure"
QMS Advisory Circular A/C No. 51C,
"Assigned Deterioration Factors for 1988 Model Year Light-Duty
Vehicles, Light-Duty Trucks, and Heavy Duty Engines"
Manufacturer's Guidance Letter CD-87-02 (LD/HD),
"Assigned Deterioration Factor Addendum"
Manufacturer's Guidance Letter CD-88-02 (LD),
"Catalyst Thermal Degradation Criteria Contained in Advisory
Circular #17F; Revision to Endnote #4"
Federal Regulations 40 CFR 80.24,
"Controls Applicable to Motor Vehicle Manufacturers"
Federal Register, February 28, 1990 (Volume 55, Number 40),
"Small volume manufacturer," Final Rule
Federal Register, July 7, 1992, (Volume 57, Number 130),
"Motor Vehicle and Engine Compliance Program Fees for
Light-Duty Vehicles; Light-Duty Trucks; Heavy-Duty Vehicles
and Engines; and Motorcycles Fees," Final Rule
Manufacturer's Guidance Letter CD-92-07 (LDV/LDT/HDV
/HDE/MC/ICI/SM), "Implementation of the Motor Vehicle and
Engine Compliance Program Fees"
"Phase-In of New Regulations (Implementation Schedule)"
"Instructions for the Preparation and Submission of 1996 & Later
MY Small Volume Application for Certificates of Conformity for
Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Engines"
Source
EPA
EPA
EPA
EPA
Publication Date
Sept. 4, 1997
Apr. 7, 1997
Mar. 19, 1997
Mar. 17, 1988
July 16,1992
Nov. 16, 1982
July 22, 1975
Dec. 4, 1986
Feb. 26, 1987
Jan. 21, 1988
Feb. 28, 1990
July, 1992
July 7, 1992
1995
Mar. 1996
-------
60
Appendix K
Important Documents - continued
Emission Certification Procedures
Title or Description
Manufacturer's Guidance Letter CD-94-14 (LDV\LDT\HD\GF),
"Assigned Deterioration Factors for Gaseous-Fueled Vehicles
and Engines"
Manufacturer's Guidance Letter Dear Concerned Party,
"Concerning Coverage of the Federal Motor Vehicle Emissions
Warranty Section 207(1) of the Clean Air Act"
Manufacturer's Guidance Letter EPCD-Large Engine-96-01,
"Streamlined Combined On-Highway and Nonroad Compression
Ignition Engine Application Format, Large Engine Guidance Document
and Announcement of Steamlined Application Workshop" and
attachment "U.S. EPA Large Engine & Evaporative Certification
Guidance (Draft)"
Manufacturer's Guidance Letter, CD-91-08 (LDV/HDE/HDV/
MC/ICI/SM), "Revised Engine Family Name and New Evaporative
Family Name"
Mobile Source Enforcement Memorandum No. 1A,
"Interim Tampering Enforcement Policy"
MSAPC Advisory Circular A/C No. 20-B, "Determination of Engine
Families and Classification of Emission Control Systems"
MSAPC Advisory Circular A/C No. 59, "Determination of Evaporative
Emission Families and Evaporative Emission Control Systems"
Title 40 Code of Federal Regulations Part 85, "Control of Air Pollution
From Motor Vehicles and Motor Vehicle Engines"
Title 40 Code of Federal Regulations Part 86, "Control of Air Pollution
From New and In-Use Motor Vehicles and New and In-Use Motor
Vehicle Engines: Certification and Test Procedures"
Title 40 Code of Federal Regulations Part 88, "Clean-Fuel Vehicles"
Title 40 Code of Federal Regulations Part 600,
"Fuel Economy of Motor Vehicles"
Federal Register, May 28, 1997 (Volume 62, Number 102),
"Control of Air Pollution From Motor Vehicles and New Motor
Vehicle Engines; Modification of Federal On-board Diagnostic
Regulations for Light-Duty Vehicles and Light-Duty Trucks; Extension
of Acceptance of California OBD 11 Requirements," Proposed Rule
Federal Register, September 21, 1994 (Volume 59, Number 182),
"Standards for Emissions From Natural Gas-Fueled, and Liquefied
Petroleum Gas-Fueled Motor Vehicles and Motor Vehicle Engines, and
Certification Procedures for Aftermarket Conversions," Final Rule
Federal Register, September 30, 1994, "Emission Standards for
Clean-Fuel Vehicles and Engines, Requirements for Clean-Fuel
Vehicle Conversions, and California Pilot Test Program," Final Rule
"California Certification and Installation Procedures for Alternative
Fuel Retrofit Systems for Motor Vehicles Certified for 1994 and
Subsequent Model Years and for All Model Year Motor Vehicle
Retrofit Systems Certified for Emission Reduction Credit"
Source
EPA
EPA
EPA
EPA
EPA
EPA
EPA
U.S. Government
Printing Office
U.S. Government
Printing Office
U.S. Government
Printing Office
U.S. Government
Printing Office
U.S. Government
Printing Office
U.S. Government
Printing Office
U.S. Governmemt
Printing Office
CARB
Publication Date
Sept. 27, 1995
July 18, 1995
Nov. 19, 1996
Dec. 12, 1991
June 25, 1974
June 27, 1974
Aug. 31, 1976
July 1, 1996
July 1, 1996
July 1, 1996
July 1, 1996
May 28, 1997
Sept. 21, 1994
Sept. 30, 1994
Nov. 21, 1995
-------
Emission Certification Procedures
Important Documents - continued
Appendix K
Title or Description
California Code of Regulations, Title 13, Section 2292.5,
"Specifications for Compressed Natural Gas"
California Code of Regulations, Title 13, Section 2292.6,
"Specifications for Liquefied Petroleum Gas"
"California Evaporative Emission Standards and Test Procedures
for 1978 and Subsequent Model Motor Vehicles"
"California Exhaust Emission Standards and Test Procedures for 1988
and Subsequent Model Passenger Cars, Light-Duty Trucks, and
Medium-Duty Vehicles"
"California Exhaust Emission Standards and Test Procedures for 1985
and Subsequent Model Heavy-Duty Diesel-Engines and Vehicles"
"California Exhaust Emission Standards and Test Procedures for 1987
and Subsequent Model Heavy-Duty Otto-Cycle Engines and Vehicles"
"California Exhaust Emission Standards and Test Procedures for
Systems Designed to Convert Motor Vehicles Certified for 1993
and Earlier Model Years to Use Liquefied Petroleum Gas or Natural
Gas Fuels"
"California Motor Vehicle Emission Control and Smog Index
Label Specifications"
"California Refueling Emission Standards and Test Procedures for
1998 and Subsequent Model Motor Vehicles"
Mail Out MSCD 97-01, "Amendments to Regulations Regarding
On-Board Diagnostic System Requirements for 1994 and Later
Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles
and Engines (OBD II)"
Manufacturers Advisory Correspondence #97-02,
"Cost Limit for High-Priced Warranted Parts of 1998 Model-Year (MY)
Passenger Cars (PCs), Light-Duty Trucks (LDTs), and Medium-Duty
Vehicles (MDVs)"
Manufacturers Advisory Correpondence #96-10,
"1998 and Later Model- Year (MY) Vehicle Emission
Configuration (VEC) Bar Codes"
Manufacturers Advisory Correspondence #95-05,
"Alternative Fuel Retrofit System Certification Procedures"
Manufacturers Advisory Correspondence #95-07,
"Alternative Fuel Retrofit System Certification Procedures for
Heavy-Duty Engine Applications"
Manufacturers Advisory Correspondence #95-10,
"Alternative Fuel Retrofit System Certification Procedures for
Light-Duty and Medium-Duty Vehicle Applications"
Letter from Colorado Department of Health and Environment,
"Important Notice - Changes in AQCC Regulation No. 14 and
EPA's Tampering Policy"
Regulation No. 14, "The Control of Emissions from
Alternative Fueled Motor Vehicles"
Source
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
CARB
Colorado APCD
Colorado APCD
Publication Date
Sept. 27, 1996
Sept. 27, 1996
Apr. 24, 1996
July 24, 1996
Mar. 24, 1994
June 24, 1996
Nov. 21, 1995
Sept. 20, 1996
Apr. 24, 1996
Jan. 1997
Apr. 14, 1997
Sept. 9, 1996
Apr. 7, 1995
Sept. 5, 1995
Dec. 6, 1995
Sept. 18, 1997
Aug. 30, 1993
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or imply its endorsement, recommendation, or favoring by the United States government or any agency
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the United States government or any agency thereof.
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Available to the public from:
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