We have the ASM2525/Curb idle and 40khm 90 second drive test.

I failled the first time without an EGR hooked up,here are the numbers.
Allowable in brackets (HC65) Tested 17 (CO%0.36) 0.00

(NO 484) Tested 1127

With the EGR hooked up I still failed Here are the numbers

Passed everthing else but NO was now 713 ppm

My Oxides of Nitrogen dropped by 414 ppm but I need another 229ppm reduction to pass.

BTW the car was at about 200- 220 degrees,should I run the fans?

Would putting the stock MAF ends on richen the mixture thereby cooling the combustion chambers reducing the NO count?

Any thought or input would be appreciated.

 

Anybody?

 

I found this while t-shooting the exact same prob with my little PU:

NOx Troubleshooting

It tends to lead down the path of bad Cat, if EGR and timing are correct.

My cat has 140,000 on it and a small, but obvious, leak at the Cat outlet. Tomm I am going to replace the cat, plugs, oil, filters (oil, air, fuel) and retest. I can let you know.

Later
Sean

 

Thanks for the link,I just put a new cat on Oct 17th

My allowable limit for HC is 65ppm on the drive and I tested at 14ppm.

My idle test had 200ppm allowable and I had 5ppm

 

Ok I think I have it figured out:

1) Change Fuel Filter

2) Change MAF to stock ends

3)Dump the ECM by disconnecting the battery

4) set the fans on low during the test.

I will post the results when I get them.