Emission Failed>>>>

97GTSTANG

Founding Member
May 25, 2000
852
0
17
Virginia
Just did Emissions today and I FAILED>...

HC ppm Limit is 76 reading is 56 PASS

CO% Limit is 0.42 Reading is 0.17 PASS

NO ppm Limit is 605 Reading is 1163 FAIL


So what could be the problem? The guy doing the emission said it can either be the O2 Sensors, EGR valve or the Cats.

Please help

Thanks

Sig below.
 
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Some tricks are:

Make sure your car is up to full operating temperature. Use high grade Fuel. A tune up can work wonders (plugs and wires if needed). Make sure your timing is not set too far advanced - the lower the timing, the lower the emissions (sounds strange, but its seems to work). A fresh oil change helps too. Also, if the readings are taken at idle and not a dyno, set your idle speed up as high as possible without going over the limit.

Good luck!

Ron

Engine Dyno
 
Today I put my car on a 4 gas analyzer just for the hell of it...


HP: 330 ppm went down to 260ppm after letting it idle for 2 mins..
02: .06
CO: 4.6
CO2: 11.56

Yep... the carbed cars were burnin the fuel better than my damn 03 was.... thank you Prochamber :D
 
I had the same problem and the tech giving my car the emissions test (after I had failed twice) told me to rev the engine to 2500 rpms for 30 seconds right before it is tested... I did it just before it was my turn in line and it worked like a charm... but it was not on a cobra, but I bet it would work for you too.
 
I will get my tools out and see if i can put it on this weekend. What do u all think causes the NOx ppm to be soo much higher. Limit is 605, my reading was 1163, thats almost twice the limit
is it because the car is running too lean or too rich?
 
I'm going to have to agree with StangFreak32. Move to a nice redneck state like Missouri. I just had my 96 cobra inspected a week ago with my new forged engine and mac long tubes with an off-road H-pipe and no mufflers. The freakin ground was shaking and the guy never even looked under the car. Sometimes it's nice to live in the middle of no where.
 
Make sure the EGR system is working properly (it's the primary emission control system charged with reducing oxides of nitrogen) and that the ignition timing is set to the factory value for the test.