United States
Environmental Protection
Agency
Office of Air
and Radiation
Washington, DC20460
August 1984
Air
&EPA
Motor Vehicle Tampering
Survey — 1983
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR AND RADIATION
MOTOR VEHICLE TAMPERING SURVEY - 1983
July 1984
Second printing, October, 1984
FIELD OPERATIONS AND SUPPORT DIVISION
OFFICE OF MOBILE SOURCES
Washington, D. C.
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TABLE OF CONTENTS
Introduction p. 1
Summary of findings p. 3
Results
Site and aggregate results p. 9
Trends—Houston and Phoenix p. 11
Types of tampering p. 13
Tampering and vehicle age p. 15
Effects of I/M on tampering p. 19
Effects of tampering on idle test failure rates p. 21
Fuel-related tampering p. 24
Truck rates p. 29
Manufacturer-specific rates ~ — — p. 30
Appendices
Appendix A: Relevant portions of the Clean Air Act p. A-l
Appendix B: Inspection and data recording procedures p. B-l
Appendix C: Classification of component condition p. C-l
Appendix D: Fuel sample collection and labeling procedures p. D-l
Appendix E: Method of application of plumbtesmo p. E-l
Appendix F: Field quality control/assurance — p. F-l
Appendix G: Form for recording refusals ————— p. G-l
Appendix H: Tampering and fuel switching by site p. H-l
Figures
Prevalence of emission control system tampering
by year of survey
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Overall and catalyst tampering prevalence by model p. 7
year of vehicle
Figure 1: Condition of Surveyed vehicles p. 10
Figure 2: Extent of tampering among vehicles with p. 10
at least one tampered component
Figure 3: Houston in longitudinal perspective ———•— p. 12
Figure 4: Phoenix in longitudinal perspective p. 12
Figure 5: Distribution of survey sample among tampering, --—-- p. 22
fuel switching, and idle test categories
Overlap of fuel switching indicators ——— —.,-,..-- p^ 27
Overlap of catalyst tampering and fuel switching __—-— p. 28
Lead concentrations of leaded fuel sampled from p. 29
unleaded vehicles
Tampering prevalence by manufacturer ——— p. 30
Tables
Truck and car tampering.rates by component/system p. 7
Overall vehicle classification by site p. 11
Prevalence of arguable tampering by component and survey year - p. 13
Table 1: Prevalence of tampering by component and survey year - p. 14
Table 2: Percent tampered and sample size by model year and p. 16
vehicle age at time of survey
Table 3: Prevalence of catalyst removal and sample size by p. 17
model year and vehicle age at time of survey
Table 4: Tampering/fuel switching prevalence in I/M and p. 20
non-I/M areas
Idle test failure rates by pollutant and. vehicle condition p. 23
Mean idle emissions ~~ p. 24
Table 5: Fuel switching rates for current survey by site p. 26
and indicator
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INTRODUCTION
Under the direction of the Field Operations and Support Division (FOSD)
of the EPA, personnel of both the EPA National Enforcement Investigations
Center (NEIC) and FOSD conducted a survey of light duty motor vehicle tamper-
ing at six U.S. urban areas from September through December of 1983. The
areas surveyed and total number of vehicles inspected are presented below:
Area inspected Number of inspections
Cook Co., IL 268
Sedgwick Co., KA 290
Houston, TX 374
Denver, CO 332
Los Angeles, CA 270
Phoenix, AZ 297
Motor vehicle emissions in urbanized areas account for nearly 90% of the
total carbon monoxide (CO) and airborne lead, over 50% of the hydrocarbons
(HC), and nearly 40% of the oxides of nitrogen (NOx) emitted to the atmosphere.
As a result, a major focus of the nation's effort to achieve compliance with
clean air standards has been the control of emissions from mobile sources.
In order to meet required emission standards, vehicle manufacturers have,
since 1968, installed a variety of control devices on new vehicles.
The 1977 amendments to the Clean Air Act (sections 203(a)(3)(A) and (B),
found in Appendix A) make it illegal for automobile dealers, repair and
service facilities, and fleet operators to disconnect or render inoperative
emission control devices or elements of design. The FOSD is responsible for
enforcing the tampering provisions of this Act.
In order to determine the pattern and incidence of tampering and fuel
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p. 2
1 2 3
switching, a series of surveys were conducted in 1978 , 1979 , 1981 , and
4
1982 . These surveys were conducted by the Mobile Source Enforcement Division
(FOSD's predecessor organization), an expert automotive consultant, and NEIC.
Consistent inspection procedures were used in all of these surveys to permit
comparisons and identification of trends.
1983 Survey Objectives
In addition to the general focus of earlier surveys on identification of
trends in rates and types of tampering, the 1983 survey is a principal measure-
ment tool in an Agency program by which credit may be granted on State Imple-
mentation Plans (SIPs) for state and local measures to reduce emissions due
to tampering and fuel switching. Data from the survey are used in a computer
model (MOBILES) along with engineering test results, to estimate both the
emission loading impact of these behaviors and the reductions that may be
achieved by various control program configurations. Sites for the survey
were chosen in light of the need for data on specific areas considering
programs, as well as the continuing need to monitor the general level and
distribution of tampering and fuel switching in the nation.
Within resource limitations, the survey was designed to:
1. Make local measurements of type and extent of tampering and fuel switching
for SIP credit purposes
1 Motor Vehicle Tampering Survey (1978), U.S. Environmental Protection
Agency, Mobile Source Enforcement Division, November 1978.
2 Motor Vehicle Tampering Survey (1979), U.S. Environmental Protection
Agency, National Enforcement Investigations Center, May 1980,
EPA-330/1-80-001.
3 Motor Vehicle Tampering Survey - 1981, Chattanooga, Tennessee and
Houston, Texas, U.S. Environmental Protection Agency, National
Enforcement Investigations Center, March 1982, EPA-330/1-82-001.
4 Motor Vehicle Tampering Survey - 1982, U.S. Environmental Protection
Agency, National Enforcement Investigations Center, April 1983,
EPA-330/1-83-001.
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p. 3
2. Extend and update the knowledge gained from earlier surveys on:
a. Rates of overall and component-specific tampering and fuel switching
b. Distribution of tampering by age and mileage of vehicle, manufacturer,
and other variables of interest
c. The effects of tampering on vehicle idle emissions
d. The effect of vehicle inspection and maintenance (I/M) programs and
anti-tampering programs on tampering and fuel switching behavior
In order to achieve these objectives, inspection teams visually examined
emission control devices and performed measurements of idle CO and HC emissions.
To provide information on fuel switching, inspectors sampled gasoline from the
tanks of vehicles (for later laboratory analysis for lead), tested for lead
deposits in tailpipes using Plumbtesmo® test paper, and checked the integrity
of the fuel filler inlet restrictor. These brief but thorough inspections
were performed with the consent of the vehicle owners in a variety of settings
more fully detailed elsewhere in this report.
SUMMARY OF FINDINGS
The proportion of sampled vehicles with at least one tampered component
is up significantly from that of any prior survey—26% compared with 17% in
1
1982 and similar rates in the other two large surveys of 1978 and 1979. For
1 Since these surveys were all different regarding sites, age distribution,
and truck proportion, caution must be exercised in making direct
comparisons.
® Registered trademark; appears hereafter without the ®. Manufactured
by Macherey-Nagel, Duren, W. Germany; marketed by Gallard-Schlesinger
Chemical Corp., Carle Place, New York.
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p. 4
areas with and without I/M programs these overall rates were 24% and 29%
respectively. The rate of arguable tampering, 30%, is down from the 38% seen
in the 1982 survey, while the malfunctioning rate increased from 1.2%
to 3% in this survey.
The component-specific rates for this survey are of considerable
interest, since they show significant increases in tampering with certain
critical components. Some of this information is presented graphically
below.
1 There were two I/M areas in the survey—Denver, CO, and Phoenix, AZ.
Denver, in addition to its conventional idle emissions program, conducts
a tampering check on later model vehicles. Because of its different
certification standards and unique control program history, Los Angeles
is not considered either an I/M area or non-I/M area, but is included
in overall rates.
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p. 5
The rate of catalytic converter tampering shows a monotonlc pattern of increase
over the five surveys, and is sharply up in 1983—a 59% increase to seven
percent of the vehicles surveyed. A portion of this increase may be due to
the increased age of the vehicles surveyed. Areas without I/M programs had
a ten percent rate, while areas with these programs held the rate to a still-
substantial five percent. Removal of the catalytic converter brings about
an average increase of 475% for HC and 425% for CO. For the three-way con-
verters on more recent models, removal may increase NOx by an average of 300%.
2
Tampering with PCV and evaporative systems, especially the latter,
mirrors the pattern of increase seen for other components. Evaporative
tampering more than tripled from the level measured in the 1982 survey, and
PCV tampering doubled. The increases in tampering with these HC control
systems is particularly puzzling, given the absence of benefits to the vehicle
owner associated with their removal or disablement. There was more evapora-
tive system tampering in I/M areas (7%) than in non-I/M areas (4%), but the
reverse is true for PCV systems—the rate is slightly higher in non-I/M areas.
EGR system tampering, long the most prevalent form of tampering in
these surveys, is exceeded in 1983 only by fuel switching. The rate is up
from 1982 by 33% to 13%. The I/M areas sampled had a slightly lower EGR
tampering rate than the non-I/M areas—12% as opposed to 15%. The impact
of EGR tampering is on NOx emissions, which may increase by an average of 175%.
Air pump system tampering (not shown) increased by over seventy percent
1 This and other emissions increases mentioned in the report originate in
the data for 3-way catalyst vehicles presented in Anti-Tampering and Anti-
Misfueling Programs to Reduce In-Use Emissions From Motor Vehicles,
EPA-AA-TSS-83-10, December 31, 1983.
2 PCV: Positive crankcase ventilation
3 EGR: Exhaust gas recirculation
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p. 6
to an eight percent level in 1983. The specific I/M areas in the sample
actually have a higher rate of air pump system tampering (9%) than non-I/M
areas (7%). Air pump disablement affects primarily HC and CO emissions,
bringing about increases of 200% and 800% respectively.
Fuel switching
Where fuel switching is defined by the presence of any of three indica-
tors , the rate is higher than that of the 1982 survey—a 32% increase to
14%. I/M areas had a fuel switching rate of 12%, while the rate was 17% in
non-I/M areas. The pattern of overlap among the three indicators is discussed
at some length in the fuel-related tampering section of this report. While the
effects of fuel switching vary depending upon its duration and a number of vehi-
cle characteristics, increases of 475% for HC and 325% for CO can easily occur.
Age of vehicle
As has been the case with past surveys, there is a clear relationship
between a vehicle's age and the probability that it has been tampered with.
This is evident in the graph on the following page which shows the rates by
model year for both overall tampering and catalyst removal. Substantial
fluctuations in age-specific rates should be expected for very old and very
new vehicles because of small sample sizes for those model years. These
age-specific rates are considered in longitudinal perspective over the several
surveys in the section of this report on tampering and vehicle age.
Indicators used are the presence of leaded fuel in the tank, a positive
Plumbtesmo test for tailpipe lead deposits, or a tampered filler inlet
restrictor. These criteria are used, of course, only with vehicles certified
on unleaded fuel.
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p. 7
OVERALL AND CATALYST TAMPERING
PREVALENCE BY MODEL YEAR OF VEHICLE
82 81 80 79 78 77 76
VEHICLE MODEL YEAR IN 1983 SURVEY
ANY
COMPONENT
CATALYTIC
CONVERTER
75
Truck rates
Rates of all types of tampering tend to be higher for light-duty trucks
than for passenger cars as shown below.
Tampering category
Overall
Catalytic converter
Air pump system
Evaporative system
PCV
EGR system
Fuel switching
Trucks
30%
12
9
7
7
16
22
Cars
24%
6
7
5
5
12
12
Total sample
26%
7
7
5
5
13
14
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p. 8
The difference in fuel-related tampering is particularly striking—both cata-
lyst removal and fuel switching are approximately twice as prevalent for
light—duty trucks as for passenger cars.
I/M programs and tampering
As indicated above, tampering rates in the survey areas with I/M pro-
grams were lower than in areas without programs. The differences, however,
were less pronounced than in previous surveys and echo the findings of the
1982 survey in New Jersey. Idle test failure rates of vehicles with different
types of tampering are discussed in a later section on this topic. These
differences by program status should be interpreted cautiously, since only
two I/M sites were included and these differed considerably from each other.
Remainder of the report
The sections of the report that follow primarily develop in greater
detail the topics touched upon in this summary. The survey history and
methods are explained in more detail, and results are broken out on a site-by-
site basis. In addition, certain topics of more specialized interest
are discussed.
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p. 9
RESULTS
The detailed results of this year's survey are presented in this section.
Topics include the tampering rates for individual sites, trends for sites
previously sampled, the various types of tampering, tampering as related to
vehicle age, the effect of I/M programs on tampering, fuel-related tampering,
truck tampering, and manufacturer-specific tampering.
SITE AND AGGREGATE RESULTS
The vehicles inspected in this survey have been classified into the same
four categories established by previous surveys: tampered, arguably tampered,
malfunctioning, and okay. Each vehicle is classified according to the most
severe state of any one component. Thus a vehicle lacking the catalytic
converter with which its configuration was certified is classified as
"tampered", regardless of the condition of the other components. If the most
severe state of a vehicle is, for example, a missing limiter cap, then that
vehicle is classified as "arguably tampered". If a malfunctioning component
is the most severe condition of any of the components, then the vehicle is
classified as malfunctioning. A vehicle is classified as "okay" only if
none of its inspected emission control components exhibit any of the negative
conditions discussed above. Criteria for classification of vehicles are
presented in Appendix B.
As mentioned in the summary of findings, the overall tampering rates
are sharply up from the 1982 survey results—a 53% increase in the percentage
with at least one tampered component. More than half of the vehicles
surveyed displayed some form of malfunction, arguable tampering, or clear
tampering of emission control system components. Figure 1 shows the distri-
bution of survey vehicles among the general categories.
The frequency distribution of tampering instances for those vehicles
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FIGURE 1
CONDITION OF SURVEYED VEHICLES
p. 10
TAMPERED
26%
MALFUNCTIONING
3%
ARGUABLY
TAMPERED
30%
FIGURE 2
EXTENT OF TAMPERING AMONG VEHICLES
WITH AT LEAST ONE TAMPERED COMPONENT
ONE
COMPONENT
48%
TWO
COMPONENTS
31Z
FOUR OR MORE
COMPONENTS
101
THREE
COMPONENTS
11Z
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p. 11
classified as "tampered" is presented in Figure 2. A majority of the
tampered vehicles have multiple components tampered, and ten percent of
them have four or more instances of tampering.
The vehicle condition classifications are broken out by site below.
With the exceptions of Houston at the high end and Los Angeles at the low,
the overall tampering rates show relatively little variation from site to
site. The high rate in Phoenix is especially interesting in light of the
area's long-standing I/M program.
OVERALL VEHICLE CLASSIFICATION BY SITE
Site
Chicago, IL
Denver , CO
Houston, TX
Los Angeles, CA
Phoenix, AZ
Sedgwick Co., KA
Entire survey
Tampered
27%
23
34
16
27
24
26
Arguably
tampered
42%
24
24
26
39
27
30
Malfunctioning
2%
2
4
3
1
4
3
Okay
29%
51
39
54
33
46
42
TRENDS - HOUSTON AND PHOENIX
Only two sites included in this year's survey have been covered in prior
tampering surveys. Houston has been studied in each survey conducted, and
Phoenix was studied earlier in the 1979 survey. The trends for these sites
are presented graphically in Figure 3 and Figure 4. A general upward
trend for Houston is evident from the chart, with a sharp increase in the
rates for this year's survey. The Phoenix rates have obviously increased
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p. 12
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FIGURE 3
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1983
YEAR OF SURVEY
FIGURE 4
PHOENIX
1979
1983
YEAR OF SURVEY
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p. 13
markedly from those of the 1979 survey. The two sets of data on Phoenix are
quite comparable with regard to vehicle procurement method and refusal rates
(inspection lanes and high refusal) but this survey examines an older fleet,
and the sample is more heavily weighted with trucks. Recent surveys in
Houston prior to this one had very high refusal rates which may partially
account for the sharp increases in rates.
TYPES OF TAMPERING
The incidence of tampering with specific emission control components
and systems for the various survey years is presented in Table 1. Only
those vehicles originally equipped with a particular component are considered
when computing the tampering or arguable tampering rate for that component.
While some component-specific trends were discussed in the summary,
attention is again directed to the increases in tampering with catalytic
converter, PCV system, and evaporative control system. Most of the
component-specific rates are higher in 1983 than for previous surveys.
Information on arguable tampering similar to that presented in Table 1
is shown below:
PREVALENCE OF ARGUABLE TAMPERING BY COMPONENT AND SURVEY YEAR
Component
Limiter cap
Fuel tank cap
Tank label
Dash label
Heated air intake
1978
65%*
0
5
1
9
1979
62%
1
4
1
8
1981
83%
1
4
0
9
1982
54%
2
4
1
6
1983
54%
3
9
1
14
* Prevalence percentages in this report have usually been rounded to whole
numbers. As a result, some of the retrospective numbers will differ
slightly from what was presented in earlier reports.
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p. 14
Table 1
PREVALENCE OF TAMPERING BY COMPONENT AND SURVEY YEAR
Component /System
EGR* system
EGR control valve
EGR sensor
Air pump system
Air pump belt
Air pump/valve
Aspirator**
Catalytic converter
PCV* system
Vacuum spark retard
Idle stop solenoid
Heated air intake
Evaporative control
system
Filler neck restrictor
1978
13%
12
5
7
6
3
***
1
3
11
1
1
3
3
1979
10%
5
7
5
4
2
2
1
3
2
1
1
2
4
1981
5%
5
5
4
4
4
0
4
2
1
0
0
2
6
1982
10%
7
7
5
5
4
1
4
3
0
0
1
2
6
1983
13%
9
12
7
7
3
1
7
5
1
1
, ****
5
7
* EGR: exhaust gas recirculation
PCV: positive crankcase ventilation
** Vehicles with aspirated air systems are not equipped with other listed
air-injection components, nor do conventional systems include aspirators.
*** Aspirators were not checked during the 1978 survey.
**** As indicated in Appendix C, some codes for this component result in the
conclusion that tampering has occurred, while others lead to a conclusion
of arguable tampering.
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p. 15
Perhaps the most interesting finding among the arguable tampering components
is the prevalence of tank label removal, which parallels the increase in
fuel switching activity otherwise indicated in this survey.
TAMPERING AND VEHICLE AGE
Table 2 presents information on the relation between vehicle age and
the prevalence of tampering for the current survey and previous surveys
extending back to 1978. In the same basic format, catalyst tampering infor-
mation as related to age is shown in Table 3. The most immediately evident
conclusion from these tables is that the likelihood of a vehicle's having
been tampered with at some point in its life increases with age. In just
the 1983 survey data, this conclusion is supported by examining the top
diagonal of Table 2 which shows an almost monotonic increase from seven
percent tampering among vehicles in their first year to 55% tampering among
the few nine-year-old 1975 vehicles sampled in the survey. Table 3 on
catalyst tampering shows a .similar, though less pronounced, increase on the
diagonal from 1% tampered among first-year vehicles to 12% among those in
their eighth year (that percentage was almost doubled in the ninth year, but
with a small sample size). This approach to reading the table has the distinct
advantage of comparing data that were all collected at one time and in one
set of locations. Using the diagonal approach, we cannot, however, entirely
disentangle the effects of age from effects attributable to model-year-specific
differences in performance and tamper-proneness that might lead to different
tampering prevalence.
Two alternative ways to read the tables, vertically and horizontally,
incur the difficulties of comparing across surveys. The effects of time and
geographic location become tied up with the primary interests in changing
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Model
Year
Table 2
TAMPERING PREVALENCE AND SAMPLE SIZE BY MODEL YEAR AND VEHICLE AGE AT TIME OF SURVEY
Year of Vehicle Life
First
Second
Third
Fourth
Fifth
Sixth
Seventh Eighth
Ninth
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
7%(182)
1(25)
2(57)
6(371)
7(298)
4%(226)
7(448)
5(63)
14(502)
10(457)
13%(206)
9(454)
9(59)
15(476)
18(395)
15%(211)
18(477)
15(79)
19(374)
22(274)
31%(288)
21(430)
21(66)
22(271)
33(276)
39%(238)
26(316)
29(52)
27(242)
32(253)
44%(190)
26(317)
32(33)
36(251)
40%(171)
37(183)
55%(89)
•o
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Table 3
PREVALENCE OF CATALYST REMOVAL AND SAMPLE SIZE BY MODEL YEAR AND VEHICLE AGE AT TIME OF SURVEY
Model
Year
Year of Vehicle Life
First
Second
Third
Fourth
Fifth
Sixth
Seventh Eighth
Ninth
1983
1982
1981
1980
1979
1978
1977
1976
1975
0(250)*
0 (57)
0(326)
0(291)
1%(225)
2(441)
2 (61)
0(445)
1(417)
5%(204)
2(428)
4 (55)
1(417)
2(377)
3%(200)
6(429)
0 (71)
2(305)
2(242)
12%(252)
4(362) 8%(213)
2 (59) 2(271)
10(48)
2(204)
11%(166)
6(257) 12%(139)
26(19) 12(139)
23%(75)
* Tampering rates have been rounded to the nearest whole percent. A zero does not necessarily
indicate the total absence of tampering, but rather a level of tampering that rounded to zero.
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p. 18
technology (for vertical comparisons) and vehicle age (for horizontal com-
parisons).
Using the horizontal approach to Table 2 we see a definite and
monotonic increase with age throughout the table for all model years except
the pre-catalyst 1974 models. The 1978 model year, for example, displayed
a seven percent tampering rate when it was first examined in the 1978 survey.
The current survey indicates that 39% of the vehicles of the same model year
(approximately six years old at the time of the 1983 survey) display some
form of tampering. As mentioned above, this conclusion involves comparing
observations made at different groupings of sites and at different times,
but the conclusion that tampering prevalence increases with age is nonethe-
less a firm one.
Vertical comparisons of different model years (and thus, generally,
across technologies) hold the age of the vehicle constant. For example,
thirteen percent of the three-year-old 1981 vehicles seen in the current
survey had some tampering. This is compared with data from the 1978 survey
on 1976 vehicles which were about three years old and had an 18% tampering
prevalence. Such vertical comparisons in these tables clearly reflect both
any differences attributable to changing technology and changes in general
tampering behavior over time. The differing site composition of the surveys
is an obvious confounding factor when the tables are read vertically. The
table on overall tampering shows no clearly discernible pattern—no sharp
decrease in overall tampering attributable to the introduction of closed-loop
emission control systems in 1981. This conclusion is reinforced by a similar
vertical reading of Table 3 on catalyst tampei^ns. The table certainly does
not support the proposition of a prophylactic effect of the post-1980
technology.
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p. 19
EFFECTS OF INSPECTION AND MAINTENANCE ON TAMPERING
Inspection and maintenance (I/M) areas require vehicles to meet specific
idle emission standards. Vehicles registered in these areas are required to
be periodically tested to assure that they comply with the specific idle
emission cut-points established by these jurisdictions. In addition to
reducing emission levels by stimulating better owner maintenance, these
I/M programs have generally been perceived to deter tampering with emission
control components. Data from previous surveys have tended to support this
perception, since I/M area tampering rates have indeed been lower than non-I/M
rates.
The 1983 motor vehicle tampering survey has incorporated two I/M sites
(Denver and Phoenix) and three Non-I/M sites (Chicago; Sedgwick County,
Kansas; and Houston). Los Angeles, CA. was the sixth site to be inspected,
but cannot be legitimately classified as either an I/M or a non-I/M site
and is thus excluded from this particular analysis.
Tampering rate differences. A comparison was made of the overall
tampering levels in I/M and non-I/M sites. This rate is 29% for the non-
I/M areas and 24% for the I/M areas. The difference for cars only is more
pronounced—29% in non-I/M areas compared with 22% in I/M areas. Table 4
presents the component or system-specific rates for I/M and non-I/M areas
differentiated by vehicle type.
These rates are significantly lower in the I/M areas for some major
components. In particular, catalytic converter tampering for cars in I/M
areas is 3% as compared with the 10% non-I/M rate for cars. Likewise, the
rate of tampering with cars' EGR systems in trie I/M areas is 10%, but 15%
in the non-I/M areas. Evaporative system rates for cars reverse this
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Table 4
TAMPERING/FUEL SWITCHING PREVALENCE IN I/M AND NON-I/M AREAS BY VEHICLE TYPE
I/M areas
Tampering
Category cars trucks
At least one 22% 36%
component
tampered
Catalytic 3 16
converter
Air pump 7 15
system
Evaporative * 6 9
control system
PCV system * 54
EGR system * 10 21
Fuel Switched 9 25
Non-I/M areas Phoenix Denver
cars trucks cars trucks cars trucks
.29% 28% 23% 44% 21% 30%
10 12 3 25 38
79 8 23 69
46 5 12 77
5 10 84 25
15 15 5 19 15 23
15 23 9 39 9 13
* Since these systems do not control tailpipe emissions of pollutants covered in I/M programs,
it can be logically argued that I/M areas should not differ from other areas with
regard to the rates of tampering with these systems.
to
o
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p. 21
pattern, with higher rates in the areas covered by I/M programs.
The truck rates reverse the pattern of differences seen for cars, with
I/M areas having higher rates on all of the tabled components except the
PCV system. These higher I/M truck rates, except for PCV and EGR systems,
are attributable mostly to the rates for the Phoenix trucks which, as Table
4 indicates, are strikingly high. Differences in age distribution between
the Phoenix sample and the rest of the survey can partially account for the
higher Phoenix truck rates. The presence of only two I/M sites in the
survey and the somewhat unusual nature of the Phoenix data point to a need
for caution in drawing any conclusions regarding differences attributable
to I/M programs.
EFFECTS OF TAMPERING ON IDLE TEST FAILURE RATES
As mentioned in the previous section, vehicles which are subject to an
I/M program must meet specific idle emission cutpoints. To assess the
effects tampering and fuel switching may have on idle failure rates, idle
emissions of vehicles have been tested against the cutpoints established by
the I/M programs where they were sampled. Vehicles in the non-I/M sites were
tested against the cutpoints specified by the New Jersey I/M program.
The results of the idle tests performed on survey vehicles are presented
in Figure 5 for vehicles in the various tampering and fuel switching cate-
gories. Only eight percent of the survey vehicles free of tampering and
fuel switching failed an idle test, while slightly more than half of the
tampered and fuel switched vehicles failed that test. Certainly these
results indicate that a substantially larger proportion of tampered and fuel
switched vehicles than intact vehicles fail an idle test at typical I/M
-------
FIGURE 5
DISTRIBUTION OF SURVEY SAMPLE AMONG TAMPERING,
FUEL SWITCHING, AND IDLE TEST CATEGORIES
Entire survey
sample
100%
Okay
42%
Arguably
tampered
30%
Tampered
26%
Not fuel
switched
96%
Fuel *
switched
Not fuel
switched
Not fuel
switched
62%
Fuel
switched
38%
Pass
61%
39%
Pass
47%
Fail
53%
These vehicles do not have any mechanical tampering, but may be fuel switched as indicated by
lead in their fuel tanks or a positive tailpipe test for lead.
NJ
NJ
-------
p. 23
outpoints. It must be noted, though, that almost half of these vehicles with
compromised emission control systems passed the idle test. Failure rates on
specific pollutants are presented below.
IDLE TEST FAILURE RATES BY POLLUTANT AND VEHICLE CONDITION
Okay
3%
HC
Arguably
Tampered tampered Cat. /Fuel*
26% 17% 30%
CO
Arguably
Okay Tampered Tampered Cat. /Fuel*
6% 19% 11% 14%
* Vehicles in this category either have their catalyst removed or have
at least one of the three indicators of fuel switching.
In general I/M sites continue to maintain lower idle test failure rates
than non-I/M sites—17% for I/M compared with 32% for non-I/M. The overall
survey rate was 24%. The two I/M areas included differed considerably in
their failure rates-the rate for Phoenix was 20%, as compared with
Denver's 14% rate.
The table on the following page presents the mean idle emission
levels for tampered and intact vehicles by type of area. The idle test mean
for tampered vehicles is sharply higher than that for intact ones. Also the
means for non-I/M areas are higher than for I/M areas. The effect of the
I/M programs, independent of differences in tampering rates, may be seen in
an examination of the "okay" levels, where the non-I/M HC level is more than
double that for the I/M areas. The difference is similar for CO—0.7% for
non-I/M versus 0.4% for I/M.
-------
p. 24
MEAN IDLE EMISSIONS
HC(ppm)
Area
Entire survey
I/M areas
Non-I/M areas
Tampered
297.0
187.3
378.7
Okay
51.5
36.1
75.8
C0(%)
Tampered
2.5
1.8
2.9
Okay
0.5
0.4
0.7
FUEL-RELATED TAMPERING
Multiple indicators. While a simple definition of fuel switching is
possible, a single indicator for detection of this activity is very likely to
underestimate its prevalence. For instance, a vehicle which was repeatedly
improperly fueled with leaded gasoline during a gasoline shortage may have a
deactivated catalytic converter, but due to proper subsequent fuel use may
have little detectable lead in its fuel tank. This situation may also
characterize the "occasional" user of leaded fuel.
In order to obtain a better picture of fuel switching, this survey
includes three indicators which, singly and in combination, may provide more
adequate information than any one measure by itself. The indicators include
fuel filler inlet restrictor tampering, a positive Plumbtesmo test for lead
deposits in the tailpipe, and the presence of more than 0.05 gram per gallon
of lead in the gasoline. While the presence of lead in the fuel provides a
very strong indication of switching, its absence does not indicate that
switching has not occurred in the past. Likewise, but for different reasons,
the other two measures individually also present the problem of incorrect
negative findings where switching has actually occurred. A vehicle with an
untampered fuel filler inlet restrictor may have been fueled at a leaded
-------
p. 25
pump with a small sized nozzle or with a funnel or similar device. The
tailpipe lead test, due to the difficulties of field administration, may
fail to indicate the presence of lead, and older vehicles may have had their
tailpipes replaced since they were operated on leaded fuel. The error in
these measures, then, is always in the direction of underestimating the
proportion of catalysts exposed to leaded fuel.
Fuel switching rates. Of the vehicles requiring unleaded fuel, 14% were
identified as fuel switched by at least one of the indicators discussed above.
Table 5 displays the rates found for individual indicators as well as the
composite rates for I/M and non-I/M areas.
While fuel switching rates have increased somewhat from those of the
1982 survey, both in general and for the individual indicators, the most
striking information in the table is the rates for I/M areas. While the
1982 survey examined different sites and comparisons are thus difficult, each
of these 1983 rates is approximately double the corresponding 1982 rates.
Indicator overlap. The survey results seem to show less overlap than one
might expect among these three indicators of the same phenomenon. The Venn
diagram below illustrates this. The incomplete overlap tends to lend credence
to the position that these measures reflect different aspects of fuel switching
activity.
Since incorrect positive indications are extremely rare for these
measures, the percentage of vehicles with at least one positive indicator
seems most reasonable as a minimum estimate of the fuel switching rate in these
cities. Reasons for the real rate possibly being higher include the negative
bias of the field-administered plumbtesmo tailpipe test and the bias always
associated with refusal to participate in a non-compulsory survey.
The latter bias has been kept relatively low in this survey since all but
-------
p. 26
Table 5
FUEL SWITCHING RATES FOR CURRENT SURVEY BY SITE AND INDICATOR
Percent with at Percent with
least one positive leaded fuel
Site indicator in tank
Chicago
Sedgwick Co., KA
Houston
All non-I/M
Denver
Phoenix
All I/M
Los Angeles*
All sites
18%
13
19
17
10
15
12
5
14
Non-I/M sites
9%
7
8
8
I/M sites
5
7
6
2
7
Percent with Percent with
tampered filler positive
restrictor tailpipe test
9%
6
9
8
4
12
8
3
7
13%
10
13
12
6
12
9
3
10
* Los Angeles is considered to be neither I/M nor non-I/M.
-------
p. 27
one of the sites involved roadside pullovers with their associated lower
refusal rates.
OVERLAP OF
FUEL SWITCHING INDICATORS
Positive
plumbtesmo
(167 cars total)
Leaded fuel
in tank
22\(115 cars total)
cars
Tampered
filler restrictor
(128 cars total
1751 total
vehicles requiring
unleaded fuel
Catalyst tampering and fuel switching. While there may be a variety of
reasons why consumers and mechanics remove catalytic converters, some of this
motivation is obviously tied up with fuel switching. The data from this
survey provide little basis for inference regarding direction of causation
or the temporal ordering of these events in the vehicle's life, but it is .
possible from the survey to at least examine the extent to which these type%
of abuse occur in conjunction. Of the catalyst-equipped vehicles in the
survey sample 16% were either catalyst-tampered or fuel switched. Thirteen
percent of the vehicles in the I/M areas surveyed, and 21% of the catalyst
-------
p. 28
vehicles in non-I/M areas had one or both of these conditions. The overlap
between the conditions can be seen in the illustration below.
OVERLAP OF CATALYST TAMPERING
AND FUEL SWITCHING
Fuel
Switching
(222 total)
Catalyst
Tamperi ng
(119 total)
Vehicles with catalyst tampering exclusive of fuel switching were relatively
uncommon in this sample—more than 60% of the catalyst tampered vehicles also
were fuel switched. On the other hand, fuel switching is by no means always
accompanied by catalyst removal. Sixty-seven percent of the fuel switched
vehicles still had their catalysts.
Gasoline lead concentrations. About half of the vehicles indicated to
be fuel switched by one of the three indicators had only trace amounts
(less than .02 gram per gallon) of lead in their fuel when inspected. These
vehicles, then, were identified as fuel switched by a tampered filler restrictor
and/or a positive plumbtesmo test for prior lead use. The chart on the
following page presents the lead concentrations in the fuel of sampled
vehicles with more than 0.05 gram per gallon in their gasoline.
-------
O LU
LU =}
O Lu
CD .-i
S£ CO
LU LU
O _J
LU l—l
40
35
30'
25-
20-
15- •
5-
0.
LEAD CONCENTRATIONS OF LEADED FUEL
SAMPLED FROM UNLEADED VEHICLES
p. 29
71
/
/
CTk
O
ir>
o
Ot
o
o
CT> O*t
o
o
CM
O
O
O
O
O
o
o
o
o
o
oo
o
o
CO
o
I O
o o
o
CT> i-i
GRAMS OF LEAD PER GALLON
Truck rates
As indicated previously, the prevalence of tampering for light duty
trucks is higher than that for passenger cars. The table on page 7 shows
the substantial differences in the rates. Each emission component for the
light duty trucks tends to have a higher prevalence of tampering than do the
cars. Catalyst and filler inlet restrictor tampering among trucks is double
the amount for cars. Fuel switching also tends to be considerably higher for
trucks—227, compared with 12% for cars.
-------
p. 30
Manufacturer—specific rates
As in most previous surveys, tampering prevalence in this survey is
higher for domestic than for foreign manufacturers, with vehicles of Japanese
manufacturers having the lowest rates. Among domestic makers, AMC and Ford
have the highest prevalence at 35%, followed by GM and Chrysler at 26% and
25% respectively. These rates are shown in the graph below.
40-.
35-•
.9 30- -
25- •
20- •
15-
o:
UJ
o
01
10-
5-
0-
TAMPERING PREVALENCE BY MANUFACTURER
V
/
/
/
/
V
/
V
/
/
/
/
/
/
/
/
/
/
/
x
/
/
/
/
/
GM FORD CHRY AMC EUROP. JAPAN.
MANUFACTURER OR MFGR. GROUPING
Manufacturer differences in overall tampering may be due to a variety of
factors including but not limited to manufacture.-specific tamper-proneness.
Market share history gives rise to differences in age distribution among
-------
p. 31
vehicles of different makes, and age is clearly related to tampering prevalence.
Additionally, certain types of vehicles (trucks, for instance) are more likely
to be subjected to tampering than others, and thus makers with production
concentrated in these types can be expected to experience higher rates.
-------
A - 1
APPENDIX A
RELEVANT PORTIONS OF THE CLEAN AIR ACT
Section 203(a)(3): The following acts and the causing thereof are prohibited —
(A) 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 compli-
ance with regulations under this title prior to its sale and delivery to
the ultimate purchaser, or for any manufacturer or dealer knowingly to
remove or render inoperative any such device or element of design after
such sale and delivery to the ultimate purchaser; or
(B) for any person engaged in the business of repairing, servicing, selling,
leasing, or trading motor vehicles or motor vehicle engines, or who operates
a fleet of motor vehicles, knowingly 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 following its
sale and delivery to the ultimate purchaser.
-------
B - 1
APPENDIX B
INSPECTION AND DATA RECORDING PROCEDURES
The inspection teams consisted of five inspectors. A designated team
leader was responsible for data and sample collection. Each vehicle in-
spection included checking all emission control systems, recording basic
data about the vehicle including the addition of certain after-market parts,
measuring HC and CO emissions at idle, obtaining a fuel sample, and using
Plumbtesmo paper to check for lead deposits in the vehicle tailpipes. The
inspections focused on 1975 and newer light-duty vehicles fueled with gaso-
line. This included both passenger cars and light-duty trucks. The condi-
tion of each emission control device was determined and recorded on the
inspection forms in the field. Categorization of the results was not made
at the time of the inspection—rather this was determined by evaluating the
recorded data subsequent to the surveys.
Below is a listing of the sites, the inspection dates, the number
of vehicles inspected, the procedures used to obtain vehicles for
inspection, and the refusal rates.
Cook County, Illinois
Method of vehicle procurement: Roadside pullover
Dates of inspections: Sept. 12 - Sept. 15, 1983
Number of vehicles inspected: 268
Refusal rate: 1%
Sedgwick County, Kansas
Method of vehicle procurement: Roadside pullover
Dates of inspections: Sept. 19 - Sept. 23, 1983
Number of vehicles inspected: 290
Refusal rate: 9%
-------
B - 2
Houston, Texas
Method of vehicle procurement:
Dates of inspections:
Number of vehicles inspected:
Refusal rate:
Roadside pullover
Sept. 26 - Oct. 1, 1983
374
Denver, Colorado
Method of vehicle procurement:
Dates of inspections:
Number of vehicles inspected:
Refusal rate:
Roadside pullover
Oct. 3 - Oct. 7, 1983
332
3%
Los Angeles, California
Method of vehicle procurement:
Dates of inspections:
Number of vehicles inspected:
Refusal rate:
Roadside pullover
Nov. 28 - Dec. 2, 1983
270
4%
Phoenix, Arizona
Method of vehicle procurement:
Dates of inspections:
Number of vehicles inspected:
Refusal rate:
I/M inspection station
Dec. 5 - Dec. 9, 1983
297
26%
DATA RECORDING FORMS
The forms on the following two pages were used for recording the survey
data in the field. The forms are of the forced choice variety to assure
consistency in coding. They are designed to facilitate direct data entry.
-------
TAMPERING SURVEY - PART A
Column ft
1 ID Number I I I I I
5 Odometer (Thou.) I I I I
8 Dash Label
0 - Not orig. equipped
1 - Functioning properly
7 - Missing item
9 Make I I I I I
13 Model I I I I I
17 Model Year III
19 Vehicle Type
1 - Car
2 - Truck(includes vans)
20 License Plate(State) III
22 Displacement / / / / /
(cubic inches or liters)
** NOTE: If engine fam. is missing or il-
legible write "missing" in item 26 and
copy all but the last 6 digits of the
VIN in item 37. DO NOT COPY SERIAL
NUMBER PORTION OF VIN.
26 Engine Family
I I I I I I I I I I I I
37 VIN (if engine fam. info not avail.)
I I I I I I I I I I I I I I
50 Originally Catalyst Equipped
(from sticker under hood or driver's
door post)
1 - Yes
2 - No
3 — Can't tell (no sticker or not
readable)
51 Idle HC / / III (in PPM)
Column
55 Idle CO I I I I I (in %)
(to 1/10 percent)
59 Plumbtesmo
P - Positive
N - Negative
60 Tank Cap
1 - Functioning properly
7 - Missing Item
9 - Malfunctioning
61 Tank Label
0 - Not orig. equipped
1 - Functioning properly
7 - Missing item
62 Filler Neck Restrictor
0 - Not orig. equipped
1 - Functioning properly
4 - Mech. disc, (widened)
7 - Missing item
63 Catalytic Converter
0 - Not orig. equipped
1 - Functioning properly
7 - Missing item
9 - Malfunctioning
64 Exhaust System
P - Original equipment
N - Non-stock
65 Exhaust System Integrity
1 - Functioning properly
(no obvious leaks)
9 - Malfunctioning
(leaks evident)
66 Oxygen Sensor
0 - Not orig. equipped
1 - Functioning properly
2 - Electrical disconnect
4 - Mech. disc, (unscrewed)
7 - Missing item
Inspector's Initials
Date / / / / / / / / /
Day Mon. Yr.
-------
Col. #
1 ID number I I I I I
5 Air Cleaner
P - Orig. equip.
6 - Non-stock
6 Exhaust Manifold
P - Orig. equip.
6 - Non-stock
7 Intake Manifold
P - Orig. equip
6 - Non-stock
8 Distributor
P - Orig. equip.
6 - Non-stock
9 Turbocharger
0 - Not orig. equipped
P - Original equipment
6 - Non-stock
A - Add-on
10 Carburetor Type
P - Orig. equip.
(non sealed.)
S - Sealed carb.
F - Fuel injection
used
6 - Non-stock carb
11 Carburetor barrels
0 - Not orig. equipped
1
2
4
12 Limiter Caps
0 - Not orig. equipped
(fuel injection)
1 - Funct. properly
4 - Mech. disconnect
(tabs broken or bent)
7 - Missing item
8 - Misadjusted (sealed
plugs removed)
TAMPERING SURVEY - PART B
Col. #
13 PCV system
0 - Not orig. equipped
1 - Funct. properly
3 — Vacuum disconnect
4 - Mech. disconnnect
(fresh air hose)
6 - Non-stock (Incl. fuel
economy devices)
7 - Missing item
14 Idle Stop Solenoid
0 - Not orig. equipped
1 - Funct. properly
2 - Elect, disconnect
7 - Missing item
9 - Malfunctioning
15 Heated Air Intake
0 - Not orig. equipped
1 - Funct. properly
3 - Vacuum disconnect
4 - Mech. disconnect
6 - Non-stock (custom
air cleaner)
7 - Missing item
(stovepipe hose)
9 - Malfunct. item
(Vac. override)
16 Evap. Control System
0 - Not orig. equipped
1 - Funct. properly
3 - Vacuum discon.
(Carb. line)
4 - Mech. discon.
(tank line)
5 - Incorr. routed hose
7 - Missing item
9 - Malfunct. item (air
cleaner unsealed)
17 Aspirated Air Injection
System
0 - Not orig. equipped
(if conventional
system or none)
1 - Funct. properly
4 - Mech. disconnect
7 - Missing item
9 - Malfunctioning
Col. #
18 Air Pump Belt (if Aspir.,
code "0")
0 - Not orig. equipped
1 - Funct. properly
7 - Missing item
8 - Misadjusted item
(loose)
19 Air Pump System(incl valve)
0 - Not orig. equipped(if
aspirated or none)
1 - Funct. properly
4 - Mech. disc, (other
than belt removal)
7 - Missing item
9 - Malfunctioning
20 EGR Control Valve
0 - Not orig. equipped
1 - Funct. properly
3 - Vacuum disconnect
7 - Missing item
9 - Malfunct. item
21 EGR Sensor
0 - Not orig. equipped
1 - Funct. properly
3 - Vacuum disconnect
5 - Incorrect hose
routing
7 - Missing item
9 - Malfunct. item
22 Vacuum Spark Retard
0 - Not orig. equipped
1 - Funct. properly
2 - Elect, disconnect
3 - Vacuum disconnect
Inspector's initials
Date /////////
Mon. Day
Yr.
-------
B - 5
The following codes were used to record data for the major system
components on the data sheets shown on pages B - 1 & B - 2.
0 - Not originally equipped
1 - Functioning properly
2 - Electrical disconnect
3 - Vacuum disconnect
4 - Mechanical disconnect
5 - Incorrect routed hose
6 - Non-stock
7 - Missing item
8 - Misadjusted item
9 - Malfunctioning
Additional codes were used for those components which could not be
classified into the above categories.
a). ID Number - Vehicles are numbered sequentially as they are inspected. This
number is preceded by a site identifying letter.
b). Odometer - mileage in thousands
c). Dash label - displays the required fuel and will be coded 'O1, '!' or '7'.
d). Make
e). Model
f). Model year - supplied by underhood emission label.
-------
B - 6
g). Vehicle type - coded as follows:
1 - car
2 - truck
h). License plate (State)
i). Displacement - as recorded by the underhood emission label.
j). Engine family - as recorded by the underhood emission label.
k). Non-serial number portion of VIN - as recorded from the passenger side of
dash under windshield or driver's door post. Recorded only if engine
family cannot be determined.
1). Originally catalyst equipped - as recorded by the underhood emission label
or driver's door panel.
m). Idle HC in ppm and CO in percent with the engine at curb idle.
n). Plumbtesmo - Plumbtesmo paper is used to check for the presence of lead in
vehicle exhaust pipes. A positive indication is coded as 'P' and a negative
as 'n1.
o). Tank cap - seals the fuel tank during normal operating conditions and will
be coded '!', '?' or '9'.
p). Tank label - displays required fuel and will be coded '0', 'I1 or '7'.
q). Filler neck inlet restrictor (unleaded vehicles only). The restrictor is
designed to prevent the introduction of leaded fuel into a vehicle requiring
unleaded fuel. It will be coded '0', flf, '4'(widened) or '7'.
r). Catalytic converter - oxidizes the HC and CO to water and C02 in the exhaust
-------
B - 7
gases. Later model catalysts also convert oxides of nitrogen. The converter
will be coded 'O1, 'I1, '?' (catalyst removed from cannister or entire
cannister removed), or '9' (high temperature discoloration, usually light
blue.
s). Exhaust system - if originally equipped a 'Pf is coded. If non-stock an 'N1
is coded.
t). Exhaust system integrity - the condition of the exhaust system is
coded as follows: 'I1 (no obvious leaks) and '9* (leaks evident).
u). Oxygen sensor - controls the air-fuel mixture going into the engine.
Primary purpose is to work with 3-way catalytic converters. The oxygen
sensor will be coded 'O1, '!', '2', '3' (unscrewed) and '7'.
v). Inspector's initials - quality assurance measure.
w). Date
x). ID number - same as (a).
The codes below are used to record data for components y through D.
0 - Not originally equipped
P - Original equipment
6 - Aftermarket or non-stock
A - Add-on equipment
S - Sealed carburetor
F - Fuel injection used
y). Air cleaner, exhaust manifold, intake manifold and distributor - will be
coded 'P1 or '6'.
-------
B - 8
z). Turbocharger -will be coded '0', 'P', '6' or 'A'.
A). Carburetor type -will be coded 'P1, 'F1, '6' or 'S1.
B). Carburetor barrels - is coded '0' or the actual number of barrels (1,2,
3 or 4).
C). Limiter caps - plastic caps on idle mixture screws designed to limit carbure-
tor adjustments. The limiter cap is coded '0', '!', '4' (tabs broken
or bent), '7* or '8* (sealed plugs removed).
D). Positive crankcase ventilation system—prevents crankcase emissions by
purging the crankcase of blow-by gases which leak between the piston rings
and the cylinder wall in the combustion chamber when high pressures are
developed during the compression and power strokes. The PCV system is
coded '0', 'I1, '31, '4' (fresh air hose), '6f (includes fuel economy devices)
or '7'.
E). Idle stop solenoid - provides an idle stop for maintaining idle speeds at
higher rpm levels and prevents the throttle plate from fully closing during
deceleration in order to minimize CO emissions. The idle stop solenoid
will be coded '0', '!', '2', '7' or '9'.
F). Heated air intake - provides warm air to the carburetor during cold
engine operation. The heated air intake will be coded '0', 'I1, '3', '4',
'6' (custom air cleaner), '7* (stovepipe hose), '9f (Vacuum override).
G). Evaporative control system - controls vapors from the fuel tank and
carburetor. Some systems have two lines, one from the fuel tank to the
canister, and one from the canister to the carburetor or air cleaner to air
purge the canister.
-------
B - 9
Other systems have a third line, usually connected to the carburetor. The
ECS is coded '0', '1', '3' (carburetor line), '4' (tank line), '5', '?'
or '9' (air cleaner unsealed).
H). The Air Injection System keeps the exhaust emission levels within the specif-
ied limits and still maintains proper vehicle performance characteristics
by extending the combustion process into the engine's exhaust system through
the injection of fresh air into the exhaust ports. The air injection system
consists of an air pump driven by a belt connected to the crankshaft pulley.
The pump directs air through a control valve and lines connected to the
exhaust manifold. An air injection system may also consist of an aspirator
located in the air cleaner that supplies air to the exhaust manifold.
a), aspirated air injection system - is coded '0' (if conventional
system or none), '!', '4', '71 or '9'.
b). air pump belt (if Aspirated coded '0' )—is coded 'O1, 'I1, '71 or
'8' (loose).
c). air pump system - for the purpose of this report, consists of the air pump
and the air pump valve and is coded '0' (is aspirated or none),
'I1, '4'(other than belt removal), '7' or '9'.
I). Exhaust gas recirculation system directs a portion of the exhaust gases back
into the cylinders to reduce the amount of NOx in the exhaust gases. The
standard EGR configuration consists of a vacuum line from the carburetor to
a sensor (used to detect engine operating temperature to activate the EGR
valve), and another vacuum line from the sensor to the EGR valve.
a). EGR control valve—is coded '0', 'I1, '3', '7' or '91.
-------
B - 10
b). EGR sensor - is coded '0', 'I1, '3', '5', '7' or '9'.
J). Vacuum Spark Retard — retarding the spark during idle delays ignition within
the combustion chamber and increases the exhaust temperature thereby prolong-
ing the combustion process and reducing HC emissions. Vacuum spark retard
is coded '0', '!', '2' or '31.
-------
C - 1
APPENDIX C
CLASSIFICATION OF COMPONENT CONDITIONS
The table below is used to classify the various system components as 'tampered1,
'arguably tampered', or 'malfunctioning'. Only those codes which are eligible
for use with a given component are listed. Codes for 'not orginally equipped'
and 'functioning properly' are not included in this table. Refer to page B - 4
for an explanation of the codes.
Codes from form
Component/system | 2 | 3 | 4
Dash Label
Tank Cap
Tank Label
Filler Neck Restrictor T
Catalyst Converter
Oxygen Sensor T T
PCV System . T T
Idle Stop Solenoid T
Heated Air Intake T A
Evaporative Control System T T
Aspirated Air Injection
System T
Air Pump Belt
Air Pump System T
EGR Control Valve T
EGR Sensor T
Vacuum Spark Retard T T
5 | 6 | 7 | 9 |
A
A
A
T
T M
T
T T
T M
T A M
T T M
T M
T
T M
T M
T T
T = tampered
A = arguably tampered
M = malfunctioning
-------
D - 1
APPENDIX D
FUEL SAMPLE COLLECTION AND LABELING PROCEDURES
A fuel sample is taken from each vehicle requiring unleaded fuel.
These samples are collected in 4 ounce bottles with a hand fuel pump. Once
the sample is drawn, the fuel is replaced with an equivalent amount of
unleaded fuel if the driver requests, and the pump is flushed with unleaded
fuel.
Each bottle is identified with a stick-on label that has the vehicle
identifying survey number on it. The vehicle identifying survey number is the
first entry on data forms described in Attachment A.
Prior to shipment from the field, a sample tag with the same identifying
number is attached to each bottle. The bottles are packaged, labeled,
and shipped to the NEIC Chemistry Branch according to the shippers requirements
and the NEIC Policy and Procedures Manual.
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E - 1
APPENDIX E
METHOD OF APPLICATION OF PLUMBTESMO
1) Clean a portion of the inside of the tailpipe large enough for the
test paper by wiping it out with a paper towel or cloth. This may be
necessary in order to wipe away soot deposits which might mask the
color change.
2) Moisten the PLUMBTESMO with distilled water and immediately* press
firmly for approximately thirty seconds against the surface to be
tested. If the tailpipe is hot you may wish to clamp the test paper
in the tailpipe using a clean clamp.
*Note; The PLUMBTESMO paper must be applied during the time that the
paper is yellow for the reaction to take place. After approx-
imately 15 seconds the yellow color disappears and the paper
is no longer effective. Excess water also interferes with
the reaction.
Care must be taken to avoid contamination of the test paper. If a
person has recently handled a test paper with a positive reaction, some
lead or reactive chemical may have been transferred to their fingers.
Handling a subsequent clean test paper may cause contamination.
3) After removing the test paper, wait approximately thirty seconds to
make a determination. A color change to red or pink splotches
indicates the presence of lead.
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F - 1
APPENDIX F
FIELD QUALITY CONTROL/ASSURANCE
Reference and calibration gases were used to assure the accuracy of the
emissions measuring instrument. Horiba gases certified by RTP were used as
reference gases. Two cylinders of reference gas were used to validate the
accuracy of the calibration gases before they were taken to the field on each
survey.
Three calibration gases (Horiba) were used. These gases were a mixture
of CO and HC in nitrogen and were used to check the instrument at least three
times daily. These calibration gases are certified by the manufacturer and the
RTP reference gases. Their approximate concentration is:
8% CO
1560 ppm HC (Hexane equivalent)
4% CO
827 ppm HC (Hexane equivalent)
1.6% CO
320 ppm HC (Hexane equivalent)
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G - 1
Location
APPENDIX G
MOTOR VEHICLE TAMPERING SURVEY
RECORD OF NON-PARTICIPATING VEHICLES
Date
TIME
MAKE
MODEL
YEAR
REASON
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Appendix H
1983 tampering and fuel switching rates — by site and I/M program status
Tampering Category
Sedgwick Los I/M Non-I/M All
Chicago Denver County,KA Angeles Phoenix Houston areas areas* sites
At least one component
tampered
Catalytic converter
Filler restrictor
PCV system
Evaporative control
system
Air pump system **
E<3* system
Fuel switching categories
Any of three
indicators ***
Habitual (leaded fuel
or tampered filler)
* Los Angeles rates are
27%
15
10
4
1
7
12
18
13
23%
4
4
3
7
6
17
10
7
not included in
** Does not include aspirated
systems .
24%
7
6
4
2
10
14
13
9
the non-I/M
16% 27%
1 7
4 13
2 7
4 6
7 11
6 8
5 15
4 13
category.
34% 24% 29% 26%
9 5 10 7
9 887
9 565
8 745
9 977
19 12 15 13
19 12 17 14
13 10 12 10
a
i
*** Indicators include the presence of leaded fuel in the tank, a tampered fuel filler
restrictor, and a positive plumbtesmo tailpipe test for lead deposits.
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