United States Air and Radiation EPA420-R-99-004
Environmental Protection April 1999
Agency
v>EPA EPA Laboratory
Evaluation of the
Aftermarket
Device Tail Pipe Cat
> Printed on Recycled Paper
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EPA420-R-99-004
March 1999
EPA Laboratory Evaluation of the
Aftermarket Retrofit Device Tail Pipe Cat
Vehicle Programs and Compliance 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 that 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.
Data, commentary and conclusions contained in this report
should not be taken out of context or restated to give alternate conclusions.
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EPA Laboratory Evaluation of Tail Pipe Cat
Introduction
This report describes the U.S. Environmental Protection Agency (EPA) laboratory exhaust
emission and fuel economy testing of a product named Tail Pipe Cat (TPC) by the Vehicle
Programs and Compliance Division (VPCD) at EPA's National Vehicle and Fuel Emissions
Laboratory (NVFEL) in Ann Arbor, Michigan. TPC is a product developed by Compliance and
Research Services, Inc. which identifies itself as CARS. The testing reported here was
volunteered for and paid by CARS as found in the following regulations: 42 USC 7525;49 USC
32918; and 40 CFR 610
EPA's analysis of the independent test laboratory data furnished with the CARS application for
evaluation demonstrated a statistically significant reduction in exhaust missions when TPC was
installed on the vehicles tested. CARS is also an independent test laboratory qualified to conduct
EPA test protocols. They furnished test data acquired in their laboratory from testing a large
volume of vehicles during the development of the TPC. However, EPA could not consider that
data because CARS has a special interest in its own product and their data would not have been
considered to be independently derived.
TPC is a supplemental catalytic converter intended to operate in conjunction with the existing
original equipment manufacturer (OEM) converter. The purpose of this product is to further
reduce the exhaust emissions of vehicles which are reaching the end of their intermediate useful
life ( 50,000 miles as identified in their application). The initial targeted market identified by
CARS in its application is for operators of large vehicle fleets such as major corporations and
government organizations. CARS makes no fuel economy claims for TPC.
Although CARS has not disclosed the specific catalytic materials nor the amount of catalyst
employed (catalyst loading) in their product, it should be presumed that it will be at least the
same, or better, than that used in the test sample when offered to the marketplace. The
TPC may also be marketed by two other names as indicated in the CARS application; these
names are Aux Cat and Cat-A-Pass.
The conclusions drawn from EPA evaluation tests are necessarily of limited applicability. An all
encompassing evaluation of the effectiveness of a product in achieving performance
improvements on the many types of vehicles that are in actual use would require a large sample
of test vehicles. This is not economically feasible in the evaluation projects conducted by EPA.
Therefore, the conclusions from such tests can be considered to be quantitatively valid only for
the specific test vehicles used; however, it is reasonable to extrapolate the results from EPA tests
to other types of vehicles in a directional manner; i.e., to suggest that similar results are likely to
be achieved on other similar types of vehicles.
-------
Test Program
The purpose of the EPA test program was to conduct a controlled technical evaluation of TPC in
a manner that would address the manufacturer's specific claims for additional reduction in
exhaust emissions with the product installed in conjunction with the vehicle's existing emission
control components. An invitation was extended to CARS to have a representative present for
all phases of maintenance and testing at the EPA test laboratory.
The confirmatory test plan developed and conducted by EPA (see Appendix: Test Plan
Agreement) and agreed to by CARS used the following two vehicles: A 1996 Dodge Caravan,
Vehicle Identification Number (VIN) 1B4G44R8TB142323, Engine Family Code
TCR3.328GKEK, 3.3 liter, with automatic transmission and 80,724 miles on the odometer at the
start of testing. This vehicle was furnished by CARS. The second was a 1996 Ford F-150,
Vehicle Identification Number (VIN) 1FTEF15N3TLA62042, Engine Family Code
TFM5.088GBJK, 5.0 liter, with automatic transmission, and 17,123 miles on the odometer at the
start of testing. The F-150 was furnished by EPA and came from its test vehicle lease program.
The federal certification standards, in grams per mile for each pollutant, for these model year
(MY) 1996 vehicles are:
Pollutant 5 years/50 K miles 11 years/120 K miles
Carbon Monoxide 4.4 5.5
Oxides of Nitrogen 0.7 0.97
Non-methane Hydrocarbons 0.32 0.40
Although the two test vehicles were light duty trucks chosen for the ease of installing the TPC,
this does not imply that the product may be difficult to install on other vehicle types nor that its
use should be limited to light duty trucks. It was merely expedient and resource effective to use
these vehicles.
Prior to testing, the test vehicles were inspected and maintenance performed identical to that
employed on consumer owned vehicles in the VPCD in-use emissions program. The vehicles
were tuned to manufacturer's specifications, and any malfunctioning part was replaced as
necessary. Engine oil and filter change is included in the maintenance procedure. Once the
testing program was started, no adjustments were made to either vehicle.
The test phases were:
1. Three Federal Test Procedure tests (FTP, the simulated city drive test) and three Highway Fuel
Economy Tests (HFET) with the vehicle in stock configuration were performed to establish the
emissions and fuel economy characteristics prior to the installation of TPC. No adjustments were
made to any engine components between tests.
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Note: Although CARS makes no fuel economy claims with use of the TPC , it is EPA policy to
conduct the fuel economy tests to determine whether there are negative effects when using any
device or fuel additive in the evaluation program.
2. After stock configuration testing, the TPC was installed in the exhaust downstream of the
stock catalytic converter per CARS' instruction and five FTP and HFET tests were conducted to
measure emissions and fuel economy. No adjustments were made to any engine components
between tests.
3. After conducting the test series with the TPC installed, each vehicle was driven 1000 miles
over the standard EPA driving course in the Ann Arbor, Michigan area to provide some degeree
of aging of the TPC.
4. An additional five FTP and HFET tests were conducted to measure emissions and fuel
economy after 1000 miles were accumulated on each vehicle. No adjustments were made to any
engine components between tests.
5. The TPC was removed after testing the product and another triplicate set of stock
configuration tests was conducted on each vehicle. Again, no adjustments were made to any
engine components between tests.
Results
All test data generated in the EPA laboratory test program are presented in Tables 1-8.
The results of the testing are shown in the three following comparisons: the results of testing
after initially installing the TPC against the stock configuration, the results of testing after 1000
miles accumulation with the TPC against the stock configuration, and the results of testing after
removal of the TPC and restoration to stock configuration against the stock configuration before
installation of the TPC.
The emissions for both vehicles in stock configuration were below the MY 1996 federal emission
standards. Although there is no federal standard for total hydrocarbons for these MY 1996
vehicles, we have provided the test results in conjunction with non-methane hydrocarbon data
since CARS had furnished this data with their application.
First Installation of the TPC
The Dodge Caravan had a 17% reduction in both non-methane hydrocarbons (NMHC) and
hydrocarbons (HC), a 30% reduction in carbon monoxide (CO), and a 38% reduction in oxides
of nitrogen (NOx). These reductions were all statistically significant improvements. There was
no significant difference in either city or highway fuel economy.
The Ford F-150 had a 4% reduction in both non-methane hydrocarbons (NMHC) and carbon
monoxide (CO), a 6% reduction in hydrocarbons (HC) and an 18% reduction oxides of nitrogen
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(NOx). The reductions in HC and NOx were statistically significant improvements; the
reductions in NMHC and CO were not statistically significant. There was no change in the city
fuel economy, but there was a two percent reduction in highway fuel economy. This change in
highway fuel economy was statistically significant.
The results of these test series are found in Tables 1 and 4.
After 1000 Miles with TPC Installed
The Dodge Caravan had an 11% reduction in both hydrocarbons (HC) and non-methane
hydrocarbons (NMHC), a 17% reduction in carbon monoxide (CO), and a 37% reduction in
oxides of nitrogen (NOx). These were all statistically significant improvements. There was no
significant difference in either city or highway fuel economy.
The Ford F-150 had a 10% reduction in both hydrocarbons (HC) and carbon monoxide (CO), an
8% in non-methane hydrocarbons (NMHC), and a 20% reduction in oxides of nitrogen (NOx).
These were all statistically significant improvements. There was no significant difference in
either city or highway fuel economy.
The results of these test series are found in Tables 2 and 5.
After Removal of the TPC - Vehicles Returned to Stock Configuration
The Dodge Caravan had a 1% increase in hydrocarbons (HC),an 11% increase in carbon
monoxide (CO), a 2% increase in non-methane hydrocarbons (NMHC),and a 4% reduction in
oxides of nitrogen (NOx). These results were not, however, statistically significant differences.
Although there was no significant difference in city fuel economy there was a 2% improvement
in highway fuel economy which was significant.
The Ford F-150 had a 2% reduction in hydrocarbons (HC), an 8% reduction in carbon monoxide
(CO), and a 19% reduction in oxides of nitrogen (NOx). There was no change in the non-
methane hydrocarbons (NMHC) emissions. These were statistically significant improvements for
NOx and CO but not for HC. There was no significant difference in either city or highway fuel
economy.
The results of these test series are found in Tables 3 and 6.
The individual exhaust gas bag data generated for all of the test series for both test vehicles can
be found in Tables 7 and 8.
Conclusions
The exhaust emissions reductions were statistically significant using the Tail Pipe Cat on both
test vehicles in the initially installed configuration as well as after one thousand miles of driving
with the device installed with two exceptions. The carbon monoxide and non-methane
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hydrocarbon reductions of four percent on the Ford after initial installation of the Tail Pipe Cat
were not statistically significant.
The impact of using the Tail Pipe Cat on the Dodge vehicle (with 80,724 miles at test start)
generated greater relative reductions in emissions than those for the Ford (with 17,123 miles at
test start). It is suspected that these differences are due to the mileage differences between the
two vehicles.
The Ford also maintained a statistically significant reduction in CO and NOx when returned to
stock configuration after removal of the Tail Pipe Cat. It is suspected that the Ford may have
"drifted" from the original stock configuration test series since removal of the device should not
have had an effect on emissions. This phenomenon did not occur with the Dodge.
Use of the Tail pipe Cat did have a beneficial effect of reducing exhaust emissions. The product
was not designed to have an effect on fuel economy, and this was confirmed in this evaluation.
Although this evaluation was confined to light duty trucks to ease installation of the device, it
would be reasonable to assume that similar results might be realized with the device installed on
light duty vehicles (i.e., passenger cars) provided that the catalyst loading is not reduced for
commercially available units.
This evaluation did not include any testing for long term durability of the device itself or the long
term durability of the vehicle with the device installed. This would have required extended
mileage accumulation which was beyond the scope of this evaluation. Therefore, no conclusions
about long term durability can be drawn from this report.
Conclusions and results of this evaluation may not be taken out of context for promotional
purposes.
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1996 DODGE CARAVAN (with 80,724 miles at test start)
TABLE 1
Initial Installation of Tail Pipe Cat Versus Stock Configuration
Pollutant/Fuel
Economy
HC
(grams/mile)
CO
(grams/mile)
NOx
(grams/mile)
NMHC
(grams/mile)
"City" Fuel
Economy (mpg)
"Highway" Fuel
Economy (mpg)
Stock Configuration
Test 1
0.215
1.593
0.549
0.189
18.8
29.6
Test 2
0.195
1.499
0.461
0.171
19.3
29.3
Test3
0.206
1.909
0.485
0.181
19.4
29.2
Average
0.205
1.667
0.498
0.180
19.2
29.4
Tail Pipe Cat Installed (No mileage accumulation)
Test 1
0.181
1.255
0.291
0.159
19.2
29.3
Test 2
0.174
1.166
0.293
0.153
19.5
29.2
Test3
0.169
1.210
0.295
0.148
19.5
30.3
Test 4
0.161
0.980
0.305
0.140
19.1
29.2
TestS
0.170
1.251
0.351
0.150
19.2
28.6
Average
0.171
1.172
0.307
0.150
19.3
29.3
Percent
Difference
- 17
-30
-38
-17
1
0
Statistically
Significant
YES
YES
YES
YES
NO
NO
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1996 DODGE CARAVAN (with 80,724 miles at test start)
TABLE 2
After 1000 miles with Tail Pipe Cat Installed Versus Stock Configuration
Pollutant/Fuel
Economy
HC
(grams/mile)
CO
(grams/mile)
NOx
(grams/mile)
NMHC
(grams/mile)
"City" Fuel
Economy (mpg)
"Highway" Fuel
Economy (mpg)
Stock Configuration
Test 1
0.215
1.593
0.549
0.189
18.8
29.6
Test 2
0.195
1.499
0.461
0.171
19.3
29.3
Test3
0.206
1.909
0.485
0.181
19.4
29.2
Average
0.205
1.667
0.498
0.180
19.2
29.4
Tail Pipe Cat Installed (After 1000 miles)
Test 1
0.187
1.307
0.279
0.168
18.8
29.3
Test 2
0.173
1.325
0.331
0.151
18.9
28.9
Test3
0.183
1.484
0.320
0.161
19.5
29.4
Test 4
0.177
1.284
0.301
0.157
18.9
28.9
TestS
0.189
1.490
0.327
0.167
19.1
29.7
Average
0.182
1.378
0.312
0.161
19.0
29.2
Percent
Difference
- 11
- 17
-37
-11
- 1
0
Statistically
Significant
YES
YES
YES
YES
NO
NO
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1996 DODGE CARAVAN (with 80,724 miles at test start)
TABLE 3
Stock Configuration After Removal of Tail Pipe Cat Versus Stock Configuration
Pollutant/Fuel
Economy
HC
(grams/mile)
CO
(grams/mile)
NOx
(grams/mile)
NMHC
(grams/mile)
"City" Fuel
Economy (mpg)
"Highway" Fuel
Economy (mpg)
Stock Configuration
Test 1
0.215
1.593
0.549
0.189
18.8
29.6
Test 2
0.195
1.499
0.461
0.171
19.3
29.3
Test3
0.206
1.909
0.485
0.181
19.4
29.2
Average
0.205
1.667
0.498
0.180
19.2
29.4
Returned to Stock Configuration
Test 1
0.211
1.926
0.474
0.185
19.3
30.0
Test 2
0.206
1.728
0.487
0.182
19.4
29.9
Test3
0.208
1.885
0.469
0.183
19.4
29.6
Average
0.208
1.846
0.477
0.183
19.4
29.8
Percent
Difference
1
11
-4
2
1
2
Statistically
Significant
NO
NO
NO
NO
NO
YES
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1996 FORD F-150 (with 17,123 miles at test start)
TABLE 4
Initial Installation of Tail Pipe Cat Versus Stock Configuration
Pollutant/Fuel
Economy
HC
(grams/mile)
CO
(grams/mile)
NOx
(grams/mile)
NMHC
(grams/mile)
"City" Fuel
Economy (mpg)
"Highway" Fuel
Economy (mpg)
Stock Configuration
Test 1
0.162
1.051
0.415
0.119
16.2
23.5
Test 2
0.151
0.941
0.421
0.108
16.0
23.3
Test 3
0.154
1.042
0.407
0.114
16.1
23.5
Average
0.156
1.011
0.414
0.114
16.1
23.4
Tail Pipe Cat Installed (No mileage accumulation)
Test 1
0.141
0.916
0.359
0.101
16.0
23.1
Test 2
0.155
1.050
0.346
0.115
16.1
22.7
Test 3
0.137
0.841
0.323
0.104
16.0
23.0
Test 4
0.148
0.983
0.324
0.114
16.1
23.2
Test5
0.141
1.001
0.349
0.107
16.2
22.8
Test 6
0.152
1.012
0.344
0.115
16.2
23.2
Average
0.146
0.967
0.341
0.109
16.1
23.0
Percent
Difference
-6
-4
-18
-4
0
-2
Statistically
Significant
YES
NO
YES
NO
NO
YES
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1996 FORD F-150 (with 17,123 miles at test start)
TABLE 5
After 1000 miles with Tail Pipe Cat Installed Versus Stock Configuration
Pollutant/Fuel
Economy
HC
(grams/mile)
CO
(grams/mile)
NOx
(grams/mile)
NMHC
(grams/mile)
"City" Fuel
Economy (mpg)
"Highway" Fuel
Economy (mpg)
Stock Configuration
Test 1
0.162
1.051
0.415
0.119
162
23.5
Test 2
0.151
0.949
0.421
0.108
16.0
23.3
Test 3
0.154
1.042
0.407
0.114
16.1
23.5
Average
0.156
1.011
0.414
0.114
16.1
23.4
Tail Pipe Cat Installed (After 1000 miles)
Test 1
0.131
0.873
0.333
0.098
16.1
23.1
Test 2
0.130
0.865
0.298
1.050
16.1
23.3
Test 3
0.141
0.899
0.346
0.841
16.1
23.4
Test 4
0.149
0.965
0.363
0.983
16.2
23.3
Test5
0.141
0.933
0.301
1.001
16.2
23.4
Test 6
0.150
0.929
0.348
1.012
16.1
23.7
Average
0.140
0.911
0.332
0.105
16.1
23.4
Percent
Difference
-10
-10
-20
-8
0
0
Statistically
Significant
YES
YES
YES
YES
NO
NO
10
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1996 FORD F-150 (with 17,123 miles at test start)
TABLE 6
Stock Configuration After Removal of Tail Pipe Cat Versus Stock Configuration
Pollutant/Fuel
Economy
HC
(grams/mile)
CO (grams/mile)
NOx
(grams/mile)
NMHC
(grams/mile)
"City" Fuel
Economy (mpg)
"Highway" Fuel
Economy (mpg)
Stock Configuration
Test 1
0.162
1.051
0.415
0.119
162
23.5
Test 2
0.151
0.949
0.421
0.108
16.0
23.3
Tests
0.154
1.042
0.407
0.114
16.1
23.5
Average
0.156
1.011
0.414
0.114
16.1
23.4
Returned to Stock Configuration
Test 1
0.155
0.925
0.339
0.114
16.2
23.5
Test 2
0.143
0.947
0.330
0.107
16.2
23.7
Test3
0.158
0.911
0.344
0.119
16.2
23.7
Average
0.152
0.928
0.338
.0.113
16.2
23.6
Percent
Difference
-2
-8
- 19
0
1
1
Statistically
Significant
NO
YES
YES
NO
NO
NO
11
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Individual Gas Bag Data for the 1996 Dodge Caravan (with 80,724 miles at test start)
TABLE 7
Test
Series
SC1-1
SC1-2
SC1-3
TPC-1
TPC-2
TPC-3
TPC-4
TPC-5
TPCM-1
TPCM-2
TPCM-3
TPCM-4
TPCM-5
SC2-1
SC2-2
SC2-3
Test
Date
8/07/98
8/11/98
8/12/98
8/14/98
8/18/98
8/19/98
8/25/98
8/27/98
9/22/98
9/25/98
9/29/98
10/02/98
10/06/98
10/14/98
10/15/98
10/16/98
Bagl
HC
0.812
0.733
0.791
0.746
0.716
0.701
0.654
0.695
0.783
0.693
0.729
0.722
0.789
0.803
0.770
0.794
Bagl
NOx
1.210
1.145
1.087
0.918
0.888
0.881
0.927
0.948
0.906
0.961
0.887
0.918
0.909
1.103
1.173
1.079
Bagl
CO
4.869
4.680
6.541
5.046
4.444
4.833
3.566
4.364
5.094
4.897
5.521
4.862
5.701
5.666
5.304
6.118
Bagl
NMHC
0.766
0.689
0.744
0.703
0.676
0.659
0.615
0.658
0.744
0.652
0.687
0.682
0.746
0.759
0.725
0.746
Bagl
FE
18.9
19.0
19.2
18.9
19.1
19.0
19.0
19.0
18.7
18.7
19.0
18.7
18.9
18.8
19.2
19.2
Bagl
HC
0.041
0.037
0.040
0.023
0.017
0.018
0.020
0.018
0.014
0.022
0.027
0.020
0.018
0.034
0.043
0.037
Bagl
NOx
0.275
0.168
0.245
0.064
0.058
0.075
0.064
0.079
0.054
0.089
0.098
0.071
0.096
0.193
0.203
0.214
Bagl
CO
0.493
0.417
0.585
0.082
0.055
0.064
0.085
0.103
0.078
0.152
0.213
0.131
0.196
0.751
0.530
0.546
Bagl
NMHC
0.024
0.021
0.022
0.009
0.005
0.006
0.006
0.006
0.004
0.008
0.014
0.008
0.005
0.015
0.027
0.020
Bagl
FE
17.7
18.6
18.6
18.5
18.8
18.8
18.3
18.4
17.9
18.0
18.7
17.9
18.1
18.5
18.5
18.5
Bag 3
HC
0.091
0.087
0.078
0.053
0.061
0.052
0.056
0.062
0.064
0.063
0.065
0.062
0.058
0.097
0.088
0.089
Bag 3
NOx
0.566
0.497
0.484
0.245
0.287
0.268
0.291
0.413
0.229
0.310
0.310
0.270
0.323
0.528
0.503
0.487
Bag 3
CO
1.192
1.139
0.907
0.597
0.784
0.638
0.716
1.067
0.756
0.839
0.839
0.753
0.747
1.312
1.279
1.215
Bag 3
NMHC
0.065
0.062
0.054
0.031
0.037
0.030
0.033
0.038
0.042
0.040
0.042
0.039
0.036
0.073
0.064
0.065
Bag 3
FE
21.1
21.3
21.4
21.1
21.3
21.4
20.9
21.1
21.0
21.0
21.5
21.3
21.5
21.6
21.6
21.6
FTP FTP
HC NOx
0.215 0.549
0.195 0.461
0.206 0.485
0.181 0.291
0.174 0.293
0.169 0.295
0.161 0.305
0.170 0.351
0.187 0.279
0.173 0.331
0.183 0.320
0.177 0.301
0.189 0.327
0.211 0.474
0.206 0.487
0.208 0.469
FTP
CO
1.593
1.499
1.909
1.255
1.166
1.210
0.980
1.251
1.307
1.325
1.484
1.284
1.490
1.926
1.728
1.885
FTP
NMHC
0.189
0.171
0.181
0.159
0.153
0.148
0.140
0.150
0.168
0.151
0.161
0.157
0.167
0.185
0.182
0.183
FTP
FE
18.8
19.3
19.4
19.2
19.5
19.5
19.1
19.2
18.8
18.9
19.5
18.9
19.1
19.3
19.4
19.4
HWY
HC
0.024
0.024
0.022
0.017
0.015
0.014
0.017
0.016
0.017
0.017
0.017
0.016
0.014
0.026
0.022
0.021
HWY
NOx
0.146
0.159
0.160
0.023
0.026
0.022
0.031
0.036
0.032
0.031
0.031
0.035
0.031
0.147
0.131
0.150
HWY
CO
0.509
0.612
0.451
0.317
0.524
0.318
0.629
0.790
0.314
0.410
0.331
0.249
0.225
0.511
0.332
0.451
HWY
FE
29.6
29.3
29 2
29.3
29.2
30.3
29 2
28.6
29.3
28.9
29.4
28.9
29.7
30.0
29.9
29.6
HC =
NOx =
co =
FE =
FTP=
HWY = HFET, Highway Test
Hydrocarbons, grams per mile
Oxides of nitrogen, grams per mile
Carbon monoxide, grams per mile
Fuel economy, miles per gallon
City FJrive Test
Test Series:
SC-1 = Stock configuration before Tail Pipe Cat
TPC = Tail Pipe Cat installed
TPCM = Tail Pipe Cat installed; 1000 accumulated miles
SC 2 = Stock configuration after removing TPC
12
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Individual Gas Bag Data for the 1996 Ford F-150 (with 17,123 miles at test start)
TABLE 8
Test Test Bag 1
Series Date HC
SC 1-1 8/26/98 0.480
SC 1-2 8/28/98 0.472
SC 1-3 9/02/98 0.497
TPC-1 9/10/98 0.441
TPC-2 9/11/98 0.495
TPC-3 9/15/98 0.420
TPC-4 9/16/98 0.452
TPC-5 9/17/98 0.453
TPC-6 9/18/98 0.470
TPCM-1 10/22/98 0.431
TPCM-2 10/23/98 0.431
TPCM-3 10/29/98 0.456
TPCM-4 10/30/98 0.460
TPCM-5 11/05/98 0.441
TPCM-6 11/20/98 0.447
SC 2-1 12/02/98 0.476
SC2-2 12/03/980.451
SC 2-3 12/08/98 0.482
Bagl
NOx
0.706
0.765
0.782
0.708
0.641
0.658
0.648
0.643
0.668
0.670
0.583
0.667
0.623
0.619
0.669
0.652
0.667
0.660
Bagl
CO
4.631
4.332
4.594
4.131
4.735
3.724
4.416
4.533
4.447
3.823
3.747
4.007
4.356
4.125
4.171
4.131
4.183
4.014
Bagl
NMHC
0.421
0.413
0.438
0.386
0.435
0.374
0.401
0.401
0.412
0.381
0.383
0.401
0.407
0.391
0.391
0.420
0.399
0.429
Bagl
FE
16.0
15.6
15.9
15.6
15.7
15.6
15.6
15.7
15.7
15.6
15.6
15.5
15.6
15.6
15.7
15.9
15.8
15.8
Bag 2
HC
0.054
0.051
0.046
0.043
0.036
0.037
0.036
0.034
0.037
0.033
0.031
0.041
0.042
0.036
0.050
0.049
0.043
0.044
Bag 2
NOx
0.249
0.233
0.205
0.151
0.150
0.130
0.144
0.158
0.151
0.128
0.140
0.167
0.195
0.116
0.163
0.173
0.132
0.169
Bag 2
CO
0.021
0.025
0.025
0.025
0.034
0.021
0.026
0.021
0.022
0.021
0.026
0.027
0.027
0.034
0.009
0.010
0.006
0.010
Bag 2
NMHC
0.016
0.015
0.015
0.011
0.006
0.013
0.011
0.011
0.011
0.011
0.008
0.013
0.015
0.012
0.014
0.070
0.059
0.084
Bag 2
FE
15.4
15.5
15.5
15.4
15.4
15.5
15.5
15.7
15.6
15.5
15.6
15.5
15.7
15.7
15.5
15.5
15.5
15.5
Bag 3
HC
0.126
0.096
0.098
0.100
0.124
0.111
0.132
0.107
0.128
0.090
0.088
0.092
0.117
0.113
0.116
0.111
0.098
0.128
Bag 3
NOx
0.509
0.514
0.505
0.488
0.492
0.434
0.417
0.485
0.463
0.462
0.382
0.442
0.487
0.411
0.453
0.415
0.446
0.435
Bag 3
CO
0.286
0.108
0.275
0.168
0.184
0.213
0.195
0.187
0.280
0.251
0.275
0.197
0.192
0.218
0.218
0.228
0.276
0.264
Bag 3
NMHC
0.083
0.055
0.057
0.057
0.079
0.072
0.091
0.068
0.087
0.050
0.047
0.053
0.076
0.073
0.073
0.070
0.059
0.084
Bag 3
FE
17.8
17.5
17.7
17.3
17.8
17.5
17.6
17.6
17.7
17.7
17.8
17.7
17.7
17.9
17.9
18.0
18.0
18.0
FTP
HC
0.162
0.151
0.154
0.141
0.155
0.137
0.148
0.141
0.152
0.131
0.130
0.141
0.149
0.141
0.150
0.155
0.143
0.158
FTP FTP
NOx CO
0.415 1.051
0.421 0.941
0.407 1.042
0.359 0.916
0.346 1.050
0.323 0.841
0.324 0.983
0.349 1.001
0.344 1.012
0.333 0.873
0.298 0.865
0.346 0.899
0.363 0.965
0.301 0.933
0.348 0.929
0.339 0.925
0.330 0.947
0.344 0.911
FTP
NMHC
0.119
0.108
0.114
0.101
0.115
0.104
0.114
0.107
0.115
0.098
0.097
0.105
0.113
0.108
0.109
0.114
0.107
0.119
FTP
FE
16.2
16.0
16.1
16.0
16.1
16.0
16.1
16.2
16.2
16.1
16.1
16.1
16.2
16.2
16.1
16.2
16.2
16.2
HWY
HC
0.033
0.031
0.031
0.031
0.030
0.027
0.029
0.026
0.026
0.028
0.028
0.030
0.031
0.031
0.039
0.033
0.031
0.032
HWY
NOx
0.359
0.353
0.363
0.327
0.369
0.311
0.303
0.313
0.314
0.268
0.254
0.267
0.291
0.278
0.300
0.275
0.287
0.335
HWY
CO
0.011
0.011
0.011
0.014
0.012
0.012
0.010
0.009
0.011
0.010
0.008
0.011
0.010
0.011
0.001
0.001
0.002
0.001
HWY
FE
23.5
23.3
23.5
23.1
22.7
23.0
23.2
22.8
23 2
23.1
23.3
23.4
23.3
23.4
23.7
23.5
23.7
23.7
HC = Hydrocarbons, grams per mile
NOx = Oxides of nitrogen, grams per mile
CO = Carbon monoxide, grams per mile
FE = Fuel economy, miles per gallon
FTP= City FJrive Test
HWY= HFET, Highway Test
Test Series:
SC 1 = Stock configuration before installing TPC
TPC = Tail Pipe Cat installed
TPCM = Tail Pipe Cat installed; 1000 accumulated miles
SC 2 = Stock configuration after removing TPC
13
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APPENDIX
The following appendix documents are only available with the hard copy version of this report copies of
which may be purchased from National Technical Information Services (NTIS). Prices and order information
may be obtained by calling: 800-553-6847.
1. Tail Pipe Cat Application for Evaluation
2. Independent Test Lab Test Reports
a. 1991 GMC Jimmy
b. 1991 Jeep Cherokee
c. 1994 Jeep Wagoneer
d. 1995 Dodge Intrepid
3. Test Plan Agreement
14
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