United States Air and Radiation EPA420-R-99-017
Environmental Protection June 1999
Agency
vvEPA Evaluation of Two
Prototype Purge Flow
Test Instruments
> Printed on Recycled Paper
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EPA420-R-99-017
June 1999
of
Martin Reineman
Regional and State Programs Division
Office of Mobile Sources
U.S. Environmental Protection Agency
NOTICE
This technical report does not necessarily represent final EPA. decisions or positions.
It is intended to present technical analysis of issues using data which are currently available.
The purpose in the release of such reports is to facilitate the exchange of
technical information and to inform the public of technical developments which
may form the basis for a final EPA decision, position, or regulatory action.
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Background:
EPA requirements for "high enhanced I/M testing" include conducting pressure and purge tests
for identifying vehicles with excess evaporative emissions, and these requirements are
published in the Code of Federal Regulations Part 51. Since the start of IM240 exhaust and
evaporative emission testing, conducting the purge test has been problematic for several
reasons. The original problems included the time constraints to run the EPA flow meter method
in high volume I/M test lanes, and the intrusive nature of the purge test which sometimes
resulted in breaking evaporative emission components while installing the purge flow meter
described in EPA IM240 and Evap Technical Guidance. These problems are related to the
design and location of vehicles' evaporative emission control systems, and the fact that they
were never designed to be evaluated with an IM240 test.
The purpose of the I/M purge test is not to provide an accurate quantitative mass measurement
of total evaporative emission hydrocarbon, but rather provide an accurate qualitative indication
of whether a vehicle has a malfunctioning purge system. Although EPA was able to develop a
qualitative purge test using a flowmeter installed between the canister and the engine intake,
this method did not translate well from the laboratory environment to actual I/M test lanes.
EPA has previously evaluated alternative purge test equipment and procedures such as the
helium tracer method, and discussed alternative concepts with auto manufacturers and
research and testing organizations.
This evaluation compared the ability of two I/M prototype instruments to correctly determine
whether the purge systems on 1981-1995 model year vehicles are functional. The instruments
were provided by Sensors Inc. and by Leo Breton and Dennis Johnson of EPA's Engine
Programs and Compliance Division of the Office of Mobile Sources.
Objective:
The purpose of this evaluation was to examine the prototypes and determine if it is desirable to
commit further development effort on these methods in pursuit of an I/M purge test for pre-
OBD II vehicles. This report presents the results of the evaluation of the two prototypes at
Automotive Testing Laboratories (ATL) in January, 1999.
An acceptable purge test requires that the instrument and test procedures meet design specific
challenges which are both vehicle and I/M test specific.
These challenges include the following vehicle specific issues:
1) The method must be applicable to the variety of evaporative emission designs used
in light duty vehicles and trucks from the 1981-1995 model years. Purge flow is
controlled by solenoids and electronic control modules (ECMs), thermal switches,
engine vacuum, and sometimes vehicle speed sensors. Purge flow may be constant
when some of the criteria above are satisfied, or modulated, cycling between zero and
maximum flow when commanded to do so. Flow rates vary greatly, typically between
10-200 cc/sec of air and hydrocarbon mixture.
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2) The canister purge lines vary greatly in their accessibility and length of line. In
approximately 30% of the in-use fleet, the canister is not visible from the engine
compartment, is sometimes sealed in body components, or is visible only from
underneath the vehicle.
3) The purge lines vary from less than a 1/4 inch outside diameter (OD) to about 1/4 inch
OD, and vary in material composition from hard plastic and age/temperature hardened
polymer lines to soft lines. Age hardened lines are often fragile and will break when
they are removed.
4) The lines are frequently located close to hot engine surfaces making access to them
a safety issue. Electrical noise and engine vibration are usually present in the engine
compartment which can interfere with electrical equipment and vibration sensitive
sensors, respectively.
Purge test criteria specific to I/M purge testing include the following test specific issues:
1) The qualitative identification of purge system failures should be accurate, with a goal
of no more than a 5% false fail rate, and a 10% false pass rate. These 5 and 10% rates
are not based on established EPA guidelines, but rather are thought to provide a
reasonable engineering objective that would be acceptable to I/M stakeholders, and
provided a common design objective for the suppliers of the two prototype purge
devices.
2) For each model year, the method should be able to be run on at least 70% of the
1981-1995 model year vehicles. 1996 and later vehicles will be able to use OBD II scan
tools to identify purge system failures. The 70% criteria is based on EPA judgement as
to what might be acceptable to I/M stakeholders.
3) Preferably, the instrument should be able to be installed without shutting off the
engine, as turning the engine off will result in delaying the start of purge flow in some
vehicles for 2-4 minutes.
4) It is desirable that the purge flow measurement be conducted simultaneously with
conducting the I/M exhaust test as this will not add to the total test time. If the method is
run simultaneously with the I/M exhaust test it must not influence the exhaust emission
results. The purge flow test is not always compatible with an idle or steady state test. If
the method must be run as a stand-alone test using a transient driving cycle, the test
length should be no longer than 60 seconds.
5) The method should be non-intrusive. Removing or cutting purge lines and installing
a flow meter is an intrusive method. The method should not leave visual evidence that a
purge test has been run.
6) The instrument should be operational under ambient conditions varying from 0-40 °C
and engine compartment temperatures of about 10-70 °C.
7) The instrument must be capable of use in an extremely rugged operational
environment.
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8) The instrument must include a means of verifying its functionality on a daily or
weekly basis.
This set of criteria, excepting items 6-8, which were not part of this evaluation, served as the
basis for deciding if the purge test prototypes warranted further development effort.
Instrument Descriptions
The description of the operating techniques behind the two prototypes is limited for two
reasons. 1) The design concepts for the two instruments are proprietary, and patents are being
explored for parts of one or both designs. 2) The designs evaluated were prototypes, and
therefore some of the limitations and problem areas observed in this test program could be
resolved by redesign and building second generation prototypes.
EPA - The EPA computer controlled prototype is based on a strain gage (load cell) design
where purge flow is sensed by comparing the purge line diameter in a no-flow state and then in
a condition when purge flow is present. The EPA method uses two pieces of hardware placed
over the purge line to make its assessment, a pneumatically actuated clamping device, which
alternately produces a flow and no-flow condition, and the sensing element which is a strain
gage load cell which measures the difference in the contraction of the purge line between a flow
and no-flow condition. The no-flow condition is achieved by momentarily clamping the purge
line using a pneumatically actuated piston. When the supply pressure to the piston is released,
the purge line returns to its undamped state and the load cell measures the contraction in the
purge line.
This measurement method is a qualitative technique, and depends on the ability to sense purge
flow a selected number of times (a minimum of eight in this evaluation) during a maximum test
period of four minutes. The EPA prototype is computer controlled and calibrated, and shows
the purge or no-purge condition by displaying the number of times purge flow is sensed. Eight
determinations of purge flow in a period of four minutes or less produce a "pass" status on the
computer monitor.
A more complete description of the EPA method is presented in Appendix 2. Appendix 3 is a
figure provided by ATL and shows the positioning of the load cell sensor and the clamping
device used for the 85 vehicles examined with the EPA tester.
Sensors - The Sensors prototype is based on an application of flow measurement used in
medical science. The basic principle is flow measurement using an approximate 0.040 in.
diameter needle probe and an application of hot wire anemometry to measure flow rate. A
computer initiates the test and displays instantaneous and cumulative purge flow over time.
When the cumulative flow equals one liter the computer displays a "pass" condition. If less than
one liter of flow is measured by the end of the four minute driving cycle, a fail determination is
made.
The method requires care to position the needle in the approximate center of the purge line
cross sectional area, which for this program, was done manually by the test technician.
Sensors has provided EPA with sketches of a "packaging concept" which would always ensure
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the needle was properly located in the flow stream.
At the time of this evaluation, the only documentation available was a brief operating procedure
supplied by Sensors and engineering concept drawings of a proposed centering and packing
design. The operating procedure is included as Appendix 4.
Test Fleet
100 1981-1995 vehicles were recruited from the Mesa, AZ I/M emission test station during the
period January 7-28, 1999. The 100 vehicle sample included a variety of model years and an
approximate 50% split of light duty vehicles and light duty trucks. No attempt was made to
obtain a sample representative of the AZ in-use fleet because the program design was simply
an evaluation of the prototype devices and did not attempt to make inferences about the in-use
test fleet. A $25 cash incentive was paid to obtain each test vehicle for a period of about 30
minutes.
Test Protocol
All tests were conducted between January 7 and January 28, 1999 in the inspection bay of the
ATL Mesa, AZ emission test facility. In its most simplistic design, the protocol called for
installing each prototype in series with a reference method and observing the response. This
was done both for vehicles in an as-received condition, and after an induced failure of the purge
system.
The test protocol consisted of the following steps:
1) Record vehicle and purge system descriptive data from each vehicle.
2) Connect a 0-10 standard cubic feet per hour (SCFH) roto-meter with a shutoff valve to
induce a "failed" mode in the canister purge system. Install a slave purge line if necessary.
3) Alternate the installation of either prototype method.
4) Exercise the vehicle at combinations of steady state operation and/or rapid accelerator
variation to induce and verify purge flow using the roto-meter. Take the appropriate time to
ensure that vehicles with operating purge systems satisfy any engine temperature, drive time
criteria, throttle actuation requirements, and, in some cases, wheel speed operation by placing
the vehicle on a hoist in the ATL inspection bay and placing the transmission in drive.
5) Compare the roto-meter and prototype device qualitative determinations of purge flow.
6) Turn the shut-off valve on the roto-meter to induce a "purge failure."
7) Repeat steps 4 and 5 with the first prototype instrument.
8) Install the second prototype and repeat steps 4 and 5.
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9) Turn the shut-off valve on the roto-meter to induce a "purge failure."
10) Repeat steps 4 and 5 with the second prototype.
Years of ATL testing experience has established that observing purge flow on the IM240 driving
cycle with a roto-meter will, with near certainty, produce the same qualitative result as an in-line
flow meter. In this study, success with either prototype device was defined as qualitative
agreement with the roto-meter method, i.e. can they determine when the purge system has
some flow, or none. Neither prototype was designed to produce accurate quantitative
correlation with a known reference method such as a totalizing flow meter.
If the prototype device could not sense flow when flow was observed with the roto-meter, the
prototype was not tested in the induced failure mode. The rationale for this was that the
prototype would again have indicated no-flow, but only because it was not performing correctly
for that particular vehicle.
Test time with each method was recorded for vehicles 33-100. Average test times for the
prototypes are calculated for the as-received tests, and do not include time to locate the purge
line or exercise the vehicle to obtain a purge condition as proven by the roto-meter. For the
induced failure mode, the test was run for four minutes, thus simulating what might be done in
an IM240 test if the purge device did not show a fast pass during the IM240 exhaust test.
Results
The evaluation program did not attempt to get a true blind test evaluation, and therefore care
was exercised in analyzing the data to attempt to simulate what would have been observed if
only the first test result with one of the prototypes was used when more than one attempt was
made to ascertain the purge system status. As this test program was part development testing
and part evaluation testing of the devices, there were instances where multiple attempts were
run with a prototype to attempt to match the purge condition shown by the roto-meter.
12 vehicles had inoperative purge systems in their as-received condition. 7 of the 12 vehicles
with true failed purge systems could be identified visually by ATL's experienced technicians. 5
of the 7 vehicles visually identified by ATL's technicians were independently identified as visual
failures by AZ I/M lane test technicians when the vehicles were returned to the I/M lane to
receive their required state inspection test.
47 of 100 vehicles had plastic lines, or polymer lines which had become hard due to aging.
The evaluation results for average test time, testability, and accuracy are summarized in Table
1. Average test time is simply the arithmetic average of the test time recorded with each
prototype on the as-received test. Testability statistics show the number of instances a slave
hose was required to test either prototype. Accuracy statistics describe the number of times
each prototype agreed with the determinations of the roto-meter, the reference method.
More detailed results of the as-received and induced failure tests are summarized in Appendix
1. Individual data sheets for each of the 100 vehicles which were analyzed to produce Table 1
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and Table1-A of the Appendix, are presented in Appendix 5, and are available upon request.
Table 1
Summary Statistics
Average Test Time
EPA
Sensors
No.
46
Time, sec
144
No.
47
Time, sec
164
Testability
Test Attempts
Slave Hose Required
No.
97
67
%
69
No.
97
8
%
8
Accuracy
As-Received Vehicles - Purge Operating
As-Received Vehicles - Tested with Prototype
Correctly Identified
False Fail
As-Received Vehicles - Purge Not Operating
As-Received Vehicles - Tested with Prototype
Correctly Identified
False Pass
Induced Failure Tests
Correctly Identified
False Pass
No.
88
85
60
25
%
71
29
No.
88
81
68
13
%
84
16
12
9
9
0
100
0
12
9
8
1
89
11
67
63
4
94
6
71
64
7
90
10
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EPA Test Results
Timeliness - Total time was recorded for installing, entering data, initializing, testing, and
removing the instrument. Average test time for 46 passing vehicles was about 2 minutes, 24
seconds.
Testability - 67 of 97 vehicles tested needed to add a slave line to install the two components of
the EPA test device. The slave line used in this test program was 3/8 inch OD fuel line hose,
and was spliced into the existing purge line designs by replacing the purge line with the longer
slave line, or by adding the slave line in series with the existing purge line. In its current
design, the purge line length required for installation of the EPA prototype was approximately
seven inches of accessible, flexible purge line. The actual lengths of the slave hose used in
this study were typically much longer than seven inches to allow more convenient underhood
access.
As-Received Tests - 88 vehicles had purge flow as observed using the roto-meter, and 12 of
the 100 vehicle sample had failed purge systems. 3 of those 12 vehicles had broken
components and could not be tested with any method, including the roto-meter.
The EPA method correctly identified 60 passing vehicles, with 43 of the passing vehicles
requiring slave hoses; 25 were false failures (29%) and 14 of the false failures were obtained
using a slave hose; 3 vehicles could not be tested due to problems with the instrument's usage
on a particular vehicle. These 3 vehicles are not included in the 25 false failures.
Of the 12 failures on the as-received tests, 9 could be tested with the roto-meter and EPA
methods, and all 9 were correctly identified using the EPA method.
Induced Failure Tests - The EPA method was tested on 67 vehicles with induced failures, 63 of
these correctly showed the no-flow condition, 4 were false passes (6%).
Overall Observations - The following observations and concerns were based on the results
above, observations during testing conducted on January 6-8, daily phone conversations with
ATL staff during the conduct of the evaluation, and in follow-up conversations with ATL during
the week of February 1.
1) The operating principle of the method was demonstrated.
2) A high false fail rate (29%) was observed.
3) False pass (6%) was not a concern.
4) At over 2 minutes per test, not including the time to locate the purge line, and not
including the vehicle operation time to induce purge, the prototype is not currently timely.
5) To avoid the use of a slave hose the ATL technicians recommended the EPA
method be no larger than the size of an amperage probe (the combined size of both
components including separation of the clamping and sensing components), which is
similar in size to the clamp on a battery jumper cable, and is typically about 2 by 4
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inches by 3/4 of an inch.
6) The method did not work on plastic or age/temperature hardened lines without a
slave hose. (67 of 97 vehicles required slave lines.)
7) Part of the setup time comes from the need to manually adjust a threshold voltage
for the sensing device due to differences in purge line diameter and hardness.
Automating this operation seems necessary to reduce the total test time.
8) The method is sensitive to the orientation of the position of the clamping device and
the load cell sensor, both the distance between them (getting the sensor too close to the
clamp sometimes produced a false reading) and whether the clamp or sensor should be
closest to the source of purge vacuum. For several tests, the orientation of the clamp
and sensor needed to be reversed to obtain purge flow.
9) 4 vehicles produced notable changes in engine speed due to clamping and
unclamping the purge line, which changes engine air flow and therefore engine speed.
Changes in engine speed are qualitatively linked to exhaust emission effects and would
not be acceptable during exhaust measurement.
10) 2 vehicles produced false results due to movement of the sensor caused by engine
vibration related to misfire, or other vehicle specific reasons.
11) Purge lines less than or equal to 1/4 inch OD, found on Toyota Corollas for
example, are too small to test in the device's current configuration.
12) The EPA method appears to lack sensitivity at the lower purge flow rates, such as
less than 3-5 SCFH.
13) The durability of a strain gage method for high volume testing was not evaluated in
this program.
Sensors Test Results
The evaluation of the Sensors device was also not a blind test because the status of the purge
system was known by the presence of the roto-meter. As with the evaluation of the EPA
device, sometimes more than one attempt was made by the test technician to obtain a valid
reading, simply to see if minor adjustments with the prototype could result in obtaining the same
result as the roto-meter result.
The Sensors device produced an indication of "pass" when the equivalent of 1.0 liter or greater
of air and hydrocarbon mixture was measured on or before 240 seconds of engine operation.
The observations summarized in Table 1 are based on the presence or absence of the "pass"
indication on the computer monitor which also displays cumulative volume and instantaneous
flow rate. The presence of voltage spikes during as-received tests can result in a false or
premature pass condition, and during the induced failure mode, a false pass determination.
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Timeliness - Using the same criteria for defining test time that was applied to the EPA method,
the average test time for installing, entering data, initializing the test, obtaining the test result,
and removing the device was about 2 minutes and 44 seconds.
Testability - 8 of 97 (8%) vehicles tested needed a slave line in which to insert the 0.040 in.
diameter probe. Although not documented why a slave line was used with the Sensors method
for a particular vehicle, the reasons may include: access to the purge line was still a problem on
some vehicles, and some of the lines were plastic or age hardened, therefore requiring
installation of a slave line. All 8 vehicles which used a slave line to test the Sensors device also
needed the slave line for corresponding tests with the EPA device.
As-received Tests - The Sensors method correctly identified 68 vehicles with passing purge
systems; 13 were false failures (16%); 7 vehicles could not be tested with the method due to
instrument problems on specific vehicles. Consistent with the treatment of the EPA data, these
7 tests were not included in the 13 false failures.
9 true failures were evaluated with the Sensors method on as-received tests. One vehicle was
incorrectly identified as a passing vehicle, and 8 were correctly identified.
Table 1-A of the Appendix indicates when a voltage spike was observed on the plot of
instantaneous flow rate versus time. These results are coded with the letter V. In theory, the
presence of one or more voltage spikes could produce a false "pass" reading. An examination
of the Sensor's results shows that the presence of voltage spikes during as-received tests did
not change the instrument's ability to correctly identify passing vehicles.
Induced Failure Tests - The Sensors method was tested on 71 vehicles; 7 vehicles showed
false passes (10%). The presence of voltage spikes on induced failure tests had a notable
impact. Had voltage spikes not been present on these tests, only 3 vehicles would have falsely
passed (4%).
Overall Observations -
1) The operating principle of the method was demonstrated.
2) The voltage spike problem resulted in false determinations of "pass" on the induced
failure tests.
3) A significant false fail rate (16%) was observed.
4) The method is not timely (164 seconds) in its current state.
5) A slave hose is generally not needed (8 of 97 vehicles) to test with the method.
6) The prototype did not use a centering method to assure the probe is located in the
center of the flow stream. Development of such a technique is required to make the
method timely and accurate.
7) No attempt was made to determine the adequacy of the silicone post treatment
applied to a hole left by removing the probe after the test. Inserting a small probe such
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as the 0.040 in. diameter needle in a purge line does not meet the definition of a non-
intrusive test.
8) Needle durability was a problem with this prototype as at least 4 probes were
required to complete the 100 vehicle test program.
Conclusions
EPA Test Device -
The following problem areas were most notable with the EPA prototype.
1) The prototype required a slave line to make a determination of purge flow due to
plastic and age hardened lines on the vehicles' purge systems.
2) In its current design, the prototype is far too large to be used in the restricted
configurations of real world vehicles' purge systems.
3) The prototype method is not timely.
4) False failure rates were high.
Items 1 and 2 above are severe limitations of the EPA prototype and it is unlikely that a second
generation prototype would eliminate these problems. Without solving these problems, and
proving success with a final prototype design in a high volume IM240 pilot study, I/M
stakeholders are unlikely to be interested in the current EPA prototype.
Sensors Test Device -
The following problem areas were most notable with the Sensors prototype.
1) The intrusive nature of the method, and its unknown effects on purge system
integrity and its possible effects when accidently applied to electrical lines and fuel lines,
are significant concerns in a real world, high volume test environment, such as IM240
test programs.
2) An automated centering method is necessary for locating the probe.
3) The prototype method is not timely.
4) Probe durability is a problem with the prototype.
Item 1 is a significant problem that cannot be addressed by designing a second generation of
prototype - inserting a probe into a purge line is fundamental to the method. Subsequent to the
January evaluation, Sensors has met with EPA and stated that preliminary testing suggested
that inserting and removing a 0.040 in. diameter probe in a sample of new and used purge lines
did not show a leak was created with their test method. Even if that is correct, or a post
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treatment of the purge line were successfully demonstrated, the perception of the intrusive
nature of this test, and its safety concerns in a high volume IM240 lane application, would likely
prevent I/M stakeholders from being interested in this concept.
Other -
7 of 12 true failures of the purge system were identified visually by the experienced ATL
technicians, and 5 of the 7 visual failures were found independently of this test program
during the AZ I/M underhood inspection in the test lanes.
Recommendations
EPA Prototype -
Due principally to testability problems (the need to miniaturize the concept and concerns about
hard purge lines which are common in older vehicles) and effects on engine speed during the
exhaust test, it is not recommended that further effort be placed on additional development of
this prototype.
Sensors Prototype -
Due to the intrusive nature of this flow measurement concept, it is not recommended that
further effort be placed on additional development of this prototype.
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Appendix 1
Results of Prototype Purge Flow Instrument Evaluation
Test results with the two prototypes are compared against readings obtained with the roto-
meter. For all methods, a "1" indicates purge flow was measured and a "2" indicates no purge
flow was measured. These values appear in the last six columns of Table 1. Two other
numeric values appear in the last six columns of Table 1, a "3", or a "4". 3 was recorded where
a test could not be run due to problems with a prototype that prevented it from being used for a
particular vehicle. A 4 appears when no result was obtained due to a tampered or missing
purge component on the vehicle. A 4 was also used to show a no-test result when a prototype
device could not measure purge flow when it was detected with the roto-meter, and it was
decided not to run a test with an induced failure because the prototype would likely have
produced a correct failure reading, but only because the prototype was not operating correctly.
The letters "V", "E", "S", and "SG" are used to provide further detail on the test results. The
letter V is unique to the Sensors prototype, and shows where a voltage spike was observed on
the plot of instantaneous flow versus time on the computer screen. The letter E appears on test
results for vehicles 25 and 37. Engine vibration during a test appeared to have falsely
influenced the purge status. The letter S was used to show which vehicles needed to have a
slave purge line installed in order to test with either the EPA or the Sensors prototypes. SG
appears on EPA results from vehicles 18, 23, 26, and 47 when the clamping and unclamping
action of the piston assembly caused a change in engine RPM at a steady state condition.
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Table 1-A
Results of Prototype Purge Flow Instrument Evaluation
Veh
No. Yr. Make Model
Odometer
Veh As-Received Test
Type Roto EPA Sens.
Induced Failure
Test
Roto EPA Sens.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
88
85
86
90
89
84
93
92
86
87
85
88
88
88
89
90
85
89
93
92
84
86
90
90
90
90
85
83
91
94
89
89
87
84
86
89
90
91
Honda
Toyota
Olds.
Honda
Dodge
Chev.
Mazda
Nissan
Volvo
Nissan
Buick
Pontiac
Chev.
Pontiac
Olds.
Dodge
Chev.
Nissan
Ford
Toyota
AMC
Mazda
Buick
Chev.
Isuzu
Nissan
Toyota
Jeep
Chev.
Nissan
Pontiac
CMC
Cadillac
Buick
Ford
Ford
Jeep
Toyota
Accord
Celica
Cutlass Sup.
Civic
Dakota
S-10 Blazer
B2000
Sentra
740 GLE
Pickup
Century
6000
Berretta
Grand Am
88
Caravan
Cavalier SW
240S
Escort SW
Pickup
Eagle
B2000
Century
S-10 Pickup
Amigo
Sentra
Pickup
Scrambler
Pickup 1500
Pickup
Grand Prix
S-15
Coupe DeVille
Sky hawk
Bronco
Escort
Comanche
Tercel
116,051
233,636
128,731
120,706
93,436
122,420
11,224
145,406
101,696
184,506
102,095
112,599
105,030
166,563
140,842
136,102
79,145
67,979
88,359
64,796
96,884
64,415
80,201
73,104
125,984
277,971
212,781
129,790
152,317
82,497
86,924
77,417
135,064
111,314
100,571
48,883
105,428
121,267
LDV
LDV
LDV
LDV
LOT
LOT
LOT
LDV
LDV
LOT
LDV
LDV
LDV
LDV
LDV
LOT
LDV
LDV
LDV
LOT
LDV
LOT
LDV
LOT
LOT
LDV
LOT
LOT
LOT
LOT
LDV
LOT
LDV
LDV
LOT
LDV
LOT
LDV
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
4
1
1
4
1
1
1
1
1
1
1
2
1
1
2
1
1
1
2S
1S
2
1S
1
1S
1S
1S
1S
2S
2S,SG
2
3
1
1
1SG
1S
1E
1SG
3
4
2S
2
4
1S
1S
1S
1S
1S
1S,E
2S
1
1
1
3
1
1
1V
2
1S
2
2
1
1S
1
1S
3
1V
1
2
1
1
1
1
1S
2
1
1V
4
1
3
4
1
1
1
1
2
2
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
4
2
2
2
2
2
2
2
2
4
2
2
4
2
2
2
2
2
2
2
3
2
2
3
2
2
2
2
1
3
2
2
2
2
2
2
2
3
4
3
2
2
2
2
1
2
3
4
2
3
4
2
2
2
2
2
1
3
2
2
2
3
2
1V
2
2
2
3
2
1
1V
2
2
3
2
2
4
2
1V
1V
2V
2
3
2V
2
4
2
3
4
1
2
2
2
2
3
2
-14-
-------
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
81
85
91
89
89
89
84
87
91
92
88
87
87
93
88
89
85
83
88
94
92
85
90
93
86
84
91
94
89
94
91
90
94
90
94
87
87
91
85
93
89
89
89
83
94
92
88
BMW
Ford
Geo
Jeep
Mazda
Dodge
Honda
Volvo
Olds.
Geo
Ford
Chev.
Chrysler
Nissan
Suzuki
Dodge
CMC
Toyota
Toyota
Suzuki
Plymouth
Chrysler
Chev.
Geo
Chev.
Ford
Sterling
Chev.
Ford
Chev.
Ford
Chev.
Plymouth
Chev.
Toyota
Ford
Cadillac
Chev.
Toyota
Toyota
Mazda
Hyundai
Nissan
Toyota
Ford
Ford
Mazda
320 I
Ranger
Storm
Pickup
626
Spirit
Civic
740 Turbo
Cutlass Calais
Storm
Festiva LX
Celebrity
5th Avenue
Quest
Samurai
Grand Caravan
S-15
Corolla
Corolla SR5
Sidekick
Grand Voyager
5th Avenue
Lumina
Storm
Caprice Classic
Mustang
827 SL
S-10 Blazer
Escort
S-10 Pickup
Ranger
Lumina
Sundance
Lumina APV
Corolla
Tempo
DeVille
S-10 Blazer
SR5 Pickup
Pickup
MX 6
Sonata
Pickup SE
Pickup 4X4
Explorer
Explorer
B2200 Pickup
113,840
118,383
98,837
112,566
52,891
129,973
143,407
90,772
148,627
111,638
100,365
95,245
137,873
82,030
99,939
167,308
150,122
63,905
111,581
70,011
100,457
128,898
98,402
106,289
39,672
157,225
83,163
92,243
130,661
88,523
97,083
140,765
127,599
135,380
27,062
84,913
65,951
127,524
210,079
80,101
85,333
99,592
40,028
131,791
72,921
67,087
87,873
LDV
LOT
LDV
LOT
LDV
LDV
LDV
LDV
LDV
LDV
LDV
LDV
LDV
LOT
LOT
LOT
LOT
LDV
LDV
LOT
LOT
LDV
LDV
LDV
LDV
LDV
LDV
LOT
LDV
LOT
LOT
LDV
LDV
LOT
LDV
LDV
LDV
LOT
LOT
LOT
LDV
LDV
LOT
LOT
LOT
LOT
LOT
1
1
1
4
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
2
1
2
2
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
2
1
1
2
2S
2
1
4
2
2S
2S
1S
1S,SG
1
2S
1
2
2
3
1S
2
1S
1S
1S
1S
2S
2
2S
2
2
1S
1
1S
1S
2S
2
1S
1S
1S
2
1S
1S
1S
1S
1S
1S
2
2S
1S
1S
2S
1
1
1
4
1
1
1V
1
1S,V
1V
3
3
1
1
1
1
2
1
1V
1
1
1
2
1V
2V
2
1
1V
2
1S
1V
2
1
3
3
2
1
1S
1
2
1
1
1
2
1
1
2
2
2
2
4
2
2
2
2
2
2
2
2
2
2
2
2
4
2
2
2
2
2
4
2
4
4
2
2
2
2
2
4
2
2
2
2
2
2
2
2
2
2
2
4
2
2
4
2
2
2
4
3
2
3
2
2
2
3
2
3
3
3
2
4
2
2
2
1
3
4
3
4
4
2
2
2
2
2
4
2
2
2
3
2
2
2
2
2
2
3
4
2
2
4
2
2
2
4
2
2
2
2
2
2
3
3
2
2
2
2
4
2
2
2
2
2
4
1V
4
4
2
2
3
2
2
4
2
3
3
3
2
2
2
3
2
2
2
4
2
2
4
-15-
-------
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
93
90
88
87
90
88
88
87
82
91
85
86
92
87
89
Toyota
Ford
Mazda
Nissan
Ford
Mazda
Toyota
Toyota
Volvo
Nissan
Subaru
Nissan
Nissan
Nissan
Toyota
Pickup 4X4
Ranger XLT
MX 6
300ZX
Escort
B2200 Pickup
Celica
Tercel
240 Turbo
Pickup
GL4WD
Sentra
Sentra
Sentra
Camry
65,149
116,195
124,231
77,574
104,012
152,446
143,112
88,070
160,714
100,276
110,062
155,826
107,788
164,662
149,919
LOT
LOT
LDV
LDV
LDV
LOT
LDV
LDV
LDV
LOT
LOT
LDV
LDV
LDV
LDV
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1S
1S
1
1S
1S
1S
1S
2S
2S
2
1
1S
2S
1S
1S
1
1
2
1
1
1
1V
2S
2
2
1
1V
2
1
1
2
2
2
2
2
2
2
2
4
3
2
2
2
2
2
2
2
2
2
2
2
2
3
4
3
2
2
3
2
2
2
2
3
2
2
2
2
3
4
3
2
2
3
2
2
1 = Purge flow measured with 0-10 SCFH rotometer, or EPA, or Sensors instrument
2 = No purge flow measured with 0-10 SCFH rotometer, or EPA, or Sensors instrument
3 = No measurement due to instrument malfunction, or false fail on as-received test
4 = No measurement due to tampering of missing vehicle components, or true fail on as-received test
V = Voltage spike observed with Sensors instrument
E = Purge result may have been influenced by engine vibration
S = Slave line required to test EPA or Sensors instrument (as-received and induced fail modes)
SG = Engine surge noted during test with EPA instrument
-16-
-------
Appendices 2-5 are available upon request from Martin Reineman, 734-214-4430, or e-mail
address, Reineman.Martin@epa.gov
-17-
------- |