New York results
 

Duke,
I passed NY inspection with the following:

1988 300ce - 85,000 miles
limits / results
HC- .80 / .44
CO- 15.00 / 2.20
NOx- 2.00 / 0.45


1998 ml 320 - 87,000 miles
HC- 220 / 164
CO- 1.2 / .59
NOx-N/A

The 300ce I adjusted myself after purchasing from PO. The ml is still at factory settings from when I purchased it new. NY has only onle test, I don't know at what mph they run the dynometer. I wasn't there when the tests were done but since I left the cars I suspect the cars were cold when the results were taken.
Thanks so much for your comments.
Richard

I'm once again struggling throught CA emissions tests and would like to share my test results with participants in this thread:

First Emissions Test since passing in 2007

MPH=15 RPM=1507 %CO2=14.9 %O2=0.2 HC(PPM)=84 CO(%)=.30 NOx(PPM) =1032 FAIL
MPH=25 RPM=1530 %CO2=14.9 %O2=0.1 HC(PPM)=43 CO(%)=.24 NOx(PPM)=525 Pass

Replaced CAT with an aftermarket model (Magnaflow).

MPH=15 RPM=1498 %CO2=11.6 %O2=4.6 HC(PPM)=28 CO(%)=.09 NOx(PPM) =944 FAIL
MPH=25 RPM=1488 %CO2=11.5 %O2=4.6 HC(PPM)=21 CO(%)=.08 NOx(PPM)=899 FAIL

Reset duty cycle (enriched mixture)

MPH=15 RPM=1520 %CO2=15.0 %O2=0.1 HC(PPM)=53 CO(%)=.03 NOx(PPM) =1508 FAIL
MPH=25 RPM=1793 %CO2=15.1 %O2=0.0 HC(PPM)=44 CO(%)=.06 NOx(PPM)=1156 FAIL

Why did CO drop so low after replacing CAT, and stay low after enriching the mixture? I would also have thought that NOx would have decreased after eliminating O2.

How old is your oxygen sensor?

Sixto
87 300D

Sorry, wrong direction. High NOx indicates faulty EGR.

[edit] Actually it indicates high combustion temperatures. EGR keeps combustion temperatures in check but the engine might be running too lean for other reasons which I think is what you tried to resolve by enriching the mixture. Do the tests end with the car at speed or does the cycle include coastdown?

Sixto
87 300D

O2 Sensor was replaced prior to test in 2005, so 4 years old. Seems to be sending feedback to Jetronic okay, but plan to check O2 Sensor electrical connection point later today.

No EGR on this model.

California emissions test, I think they collect all measurements at specified velocity (15mph & 25mph).

Yea, I've read ALL the material from the experts here on NOx formation at 4000F - peak combustion temperature. If I am unable to get NOx undercontrol via the related Jetronic adjustments, I'm afraid I'm going to have to retard timing through the changing of that little resister (I'd appreciate it if someone can direct me to instructions on that).

What I still don't get is the significant reduction of CO, and whether that has a positive or a negative impact on NOx formation.