[Rmonkey]

Well, I passed another Drive Clean test yesterday. Although 1 test was "just" close enough.

ASM2525 TEST:
Limit Reading
HC ppm 82 64
CO% 0.46 0.28
NO ppm 633 632

Anyone give suggestions on what may be causing the high nitrous reading? Reading over the literature from the testing centre, it basically says everything in the car may be wrong if this reading is too high.

Thanks.

 

[repinS]

keep trying simple, cheap things first: try cleaning out your EGR valve, if at all possible.

 

[TRDragoon]

its probably the inspector didn't warm up your car enuff....

seen 2 different inspecter test the same car, one failed since the car wasn't warm and one passed cuz he took his time....

anyhow, congrat!:thumbup:

 

[CDub LXi]

In TN, the HC limit is 220 or something like that and we don't test for NO here.

I don't know if warming the car up would change your number because you're passing the CO alright. Usually people say to warm your car up so the cat is operating correctly which will cause you to fail if not. I usually drove my car about 15 minutes before I went to the testing station.

Where I live now there is no emissions!!

 

[Rmonkey]

It's about a 10 minute drive to get there, then I had to wait 10 minutes for the clerk. I'm sure it didn't have a chance to warm up much.

 

[CDub LXi]

Was it running when you were waiting for the clerk? If so then there is no way it wasn't warmed up enough...

 

[powderblue91]

high NOx is caused by a few things. O2 sensor bad, EGR valve busted or not clean, catalytic converter (if you have a 3 way cat [91 and later]) basically when the combustion chamber temps are too high NOx is produced.