I have an 87 190E 2.6 with 115K on the clock. I got the dreaded registration renewal in the mail that stated that I had to have the car smogged at a "Test Only" station. So I changed the O2 sensor last night just to be on the safe side. The car has had new plugs and ignition wires within the 3K miles. All morning I drove the car hard to really heat up the cat. Took the car into the test only station...and she passed. I have to say waiting for the results felt like I was back in college waiting for my girlfriends pregnancy test results. Now as I look at the report it looks like they made a mistake in that it says the car is a four cylinder 2.3L. Oh well, I figure the 2.3L passing limits are lower if anything. Here are the results:

15mph
RPM 2225
CO2% 14.6
O2% 0.4
HC ppm 66 (Max 118)
CO% 0.21 (Max 0.75)
NO ppm 699 (Max 799)

25mph
RPM 2769
CO2% 14.4
O2% 0.6
HC ppm 44 (Max 93)
CO% 0.07 (Max 0.63)
NO ppm 334 (Max 738)

Those are good HC numbers for a 2.6, but could be better as the O2 is fairly high, which, if consumed in the converter, would lower HC and CO. Also, your NOx is high.

Do you have the data from the last test to compare the improvement, if any?

Did you go to a drive through test only station with a short line and keep the engine revs up while waiting?

For comparison my last numbers were (HC, CO, NOx, O2):

15 MPH, 1657 revs: 113. 0.36, 261, 0.1
25 MPH, 2665 revs: 058, 0.18, 188, 0.0

If the converter was hotter during the 15 MPH test, the 0.1% O2 could be consumed to further reduce HC and CO. The 15 MPH test heats up the converter to the point where it is "100 percent efficient" during the 25 MPH test - all O2 is consumed - but the HC and CO is still higher that average for the year group. NOx is about average.

The difference in revs is because my car has a manual trans. and both tests must be run in second gear to be within the RPM limitations.

I'm due again in February, and I'm sure I will be directed to a "test only station" being as how ours cars have been tagged by the BAR as "high emitter profile", but there is a drive through test only station not far from me that is cheap and convenient, so I would probably go there anyway.

I think one of the "problems" with these engines is the semi-hemispherical combustion chamber. It has a fairly large quench area that probably increases engine out HC relative to a design with a smaller quench area.

Duke

Actually these results have to be taken with a grain of salt as the machine thinks the car was a 2.3L 4 cylinder. I watched the tach as they were running the test and there was no way that the rpms were as high as they indicate on the report. For the 15 mph test, the tach was reading about 1700 rpm. I don't know how much of the readings would be affected by this "error". I had to wait for one car to be tested and I let the car idle during this time. So the cat was warm at best for the 15mph test. But they did have to stop the test and let the car sit and idle for 180 seconds so running the idle at 2K likely wouldn't have helped much. They did run the fan infront of the car but the temp guage was sitting at 100C. For a catalytic converter with 115K....I'm happy with the NOx results. The last test run two years ago was not performed on the dyno and just an idle and high idle test. If those results will help in your data collection I can post them as well.

If they type in the wrong displacement, it would have no impact on measured emissions, but might affect the test weight and emission limit.

Most VINs are now bar coded onto the registration form, and when scanned will show correct data for the engine because there is an engine code in the VIN field.

Yes, I would like you to post the two-speed no load test numbers from two years ago.

Also, what is the "test weight" and "VLT record #" on your report from the recent test. These are in the data field at the top of the test report.

The catalyst cools off at idle, so while waiting you are best off to keep the revs at 2000 with the A/C on and widows open to keep as much load on the engine as possible. Based on my IR gun measurements, the converter inlet surface temp cools off several hundred degrees after five minutes of idling, after driving the car in normal urban traffic.

With an auto trans the engine might still be in first gear during the 15 MPH test, which has higher relative load the the 25 MPH test, which is likely in second gear. Thus, with and auto trans the revs at both speed will be close to the same.

The load is programmed into the test software based on vehicle weight and aerodynamic characteristics. Though the test is run at steady speed, the load is greater than required to maintain a the steady speed on a level road. That's why the test is called "acceleration simulation mode". It's essentiall yequivalent to going up a hill at steady speed.

Duke

I was interested to see how close your 190E 2.6 emissions were to the test limit (even with the mistaken engine type).

I had my 1991 420SEL (W126) smogged a few weeks ago, also at a test-only station (again, because CARB has labeled these cars as high-profile emitters), and my results were only a small fraction of the allowable limit in all cases. (I can't recall the results from memory, but seem to think they were all around 10% or less of the allowable limit.)

The place I had it done was pretty crowded, so the car was fully warmed up by the drive to the test station, but then was sitting off for 45 minutes. Then, when I was called, they had me drive it to the end of the street (2 blocks) and back, just prior to the test.

What really frosted me was four years ago, when the car passed all of the actual emissions tests, but the mechanic (this was at an M-B dealer) said that I had a clogged crankcase breather pipe (actually a metal tube), and so he had to mark down a failure (of the EGR system). Replacing this tube involved several hours of labor and a fair amount of money. Afterwards the emissions readings passed again, with exactly the same values. Perhaps I was taken for a ride on this one.

Bob Schleicher
1991 420SEL, 172,000 miles

Duke, here are the results from the previous smog checks (back to 97). Test weight was 3100 and the reason for the test is "High Emitter Profile". I forgot to get the VLT record #. What does the "VLT #" reflect?

2002
RPM 2461
HC (Max 140) 37
CO (Max 1.00) .08
CO2 14.5
O2 0.4

RPM 823
HC (Max 120) 68
CO (Max 1.00) .02
CO2 14.5
O2 0.5

2000
RPM 2330
HC (max 140) 44
CO (Max 1.00) .16
CO2 13.7
O2 4.1

RPM 700
HC (Max 120) 120
CO (Max 1.00) .05
CO2 13.7
O2 4.1

1999
RPM 2687
HC (Max 140) 80
CO (Max 1.00) .32

RPM 700
HC (Max 120) 52
CO (Max 1.00) .04

1997
RPM 2486
HC (Max 140) 82
CO (Max 1.00) .29

RPM 705
HC (Max 120) 57
CO (Max 1.00) .02

From www.smogcheck.ca.gov

VLT Record #: Your vehicle's record on the Bureau of Automotive Repair's Vehicle Lookup Table (VLT). The table contains specific information for each vehicle model and engine combination available. Information from the VLT regarding your vehicle's weight and aerodynamic resistance allows the Smog Check emissions analyzer to correctly set the resistance on the dynamometer (a treadmill-like device used to test vehicles in the smoggiest urban areas of the state).

All CA owners should browse this site. There is lots of good information, and since many of our cars have been tagged as "high emitter profile" everyone needs to get educated and understand how to manage your test.

The VLT # for my car is 10038 and the the test weight is 3250. I'd still like to see your VLT # to verify if they did ID your car incorrectly. Do you recall that they scanned in the VIN from the renewal form? Did they get the VIN correct or mess up the engine code?

Thanks for posting the data. I suspect the cat was not fully warmed up during the 2000 test. My first test, two-speed idle test, in '91 at 39K miles was very good, but the second test in '93 (at 49K) idle HC went from 9 PPM to 76, 99 (1 PPM under the limit) in '95 and continues to be high ever since including my ASM tests (especially at 15 MPG), which began in 97.

It's interesting that my car has low NOx and yours is high. I never understood why they went to EGR in '89, and I have verified that the '89 camshaft is the same as '88, so they didn't reduce overlap. (More overlap increases exhaust gas residual, which acts like an "internal" EGR system.)

Duke

Okay so the VLT Record # is 09424. Correction on the test weight 3125. The Vin and plate number are correct but the mileahe is wrong by one digit (these guys aren't the sharpest around). I believe they scanned the renewal form as they specifically asked me for it when signing the car in. Do you have a link to the VLT table itself? I tried searching the BAR site and came up with nothing. Thanks.

The site doesn't list the VLT #s - just has that explanation of what it means.

I sometimes think there are more emission tests run with errors than error free. I've had a few discussions with the BAR about this being as how they consistently misidentify my Cosworth Vega, and the DMV refuses to apply the proper engine code to the VIN. GM assigned the alphabet character "O". DMV refuses to change it from numeric "0".

The 3125 test weight sounds about right if it really was a 2.3. They use the EPA certification weights, which are subdivided into 125 pound increments.

Scanning the VIN from the bar code should pull the proper data from the VLT, including engine size, but errors still seem to crop up, and the reason is not clear to me.

I would suggest that you double check the VIN on the registration form to the actual VIN placard behind the windshield. There could be an error in the engine code. The VIN has 14 characters so errors are probably not that uncommon.

Duke

Well, I went to the garage and checked the VIN on the car with the one on the smog test report and it matches. I guess I'll see what happens in two years. I did look at all the older test reports and they all indicate a six cylinder so I think this was a "Fat Finger" error. Regardless I'm just happy to have passed the test. The effort and expense I had to go through smogging my 944 Turbo was enough to make me consider not fixing the A/C on the 190E last summer.

Well, it is time to bid the 190e farwell as we purchased an ML500 to cart my wife and daughter around. I smogged the 190e to get it ready for sale.....here are the results:

15mph
RPM 1469
CO2% 14.00
O2% 1.15
HC ppm 115 (Max 116)
CO% 0.22 (Max 0.74)
NO ppm 560 (Max 791)

25mph
RPM 1460
CO2% 14.00
O2% 1.05
HC ppm 60 (Max 91)
CO% 0.10 (Max 0.62)
NO ppm 155 (Max 730)

Mileage is now 125K....it's going to be a sad day to see this car go.

Would you double check the report's O2 readings for me and list the software version/EIS number (located just above the signature block). My recent test was 0403/ES974825.

It doesn't make sense to have over one percent 02, and unless BAR changed the format on the test report since my 190E 2.6 was tested last March, O2 is reported with two digits to the nearest tenth percent such as 0.2

Is O2 now reported to the nearest hundreth percent? Or is it now PPM?

If the lambda system and catalyst are operating at near maximum efficiency the O2 reading should be no more than 0.1 percent (or 1000 PPM) and preferably 0.0.

Duke

Hello Duke, the O2 numbers are exactly as printed on my VIR Report. The heading just states "O2 (%)". The EIS number is 310/WP391878. I will have to check the VIR Report on the smog that was done on my ML500 although that test is only the idle test and I'm not sure if they report on O2.