I have been cursed with this truck to say the least. Just when I think it's all going good, and it's up for sale it FAILED the California smog test. Does anyone know what the numbers mean? I'm so tired of sinking money into this truck, my next option is to part it out! Has anyone had SMOG issues?

 

give us the numbers and we may be able to help ya.

 

Ok here's what I got:

15MPH test
HC (PPM) Max 85, I had 126
CO% Max 0.58, I had 0.57 (which I think that one is ok)
NO (PPM) Max 488, I had 3099

25MPH test
HC (PPM) Max 50, I had 102
CO% Max 0.72, I had 0.62
NO (PPM) Max 741, I had 2072

I feel like I have my hands tied with this one? I just want to sell it and now I have to deal with this? Does anyone think a new Catalytic would help? I put a new magnaflow one on 8 months ago.....

 

are you getting any codes from the trucks computer?

 

ill see what my work advises with these numbers on monday.

in the meantime, have you replaced the O2 sensor?

You can pay the dealership to scope it and give an accurate diagnosis (usually about $85) and then depending on your skills you might be able to fix it yourself.

 

Went by the mechanics shop who changed my computer, and asked his advice he thinks it's the EGR valve. Did any of you guys find out anything? The truck is sending no codes at all.

 

get a vacuum tester and see if the EGR valve will hold a vacuum. If not youve got a problem.

with excessive HC and NO heres a list of things to check:

Gas in oil
leaky fuel injectors
bad O2 sensor (most likely cause)
Ignition and wires for poor connection (whens the last time she had a tune up?)
engine speed sensor (without CEL codes I doubt this is a problem)
Vacuum leaks.

hope that helps.

 

I checked the EGR tonight and it seems to be working fine, I tested it with the truck running. I went ahead for piece of mind afterwards and pulled it off to clean it too. It looks like it may be the O2 sensor then. If my O2 was bad wouldn't I get fault code?

 

not always, I replaced mine and found the wires had melted on the exhaust and no engine codes were displayed.

 

My 90 failed about 8 years ago whenI lived in Ca. I replaced the CAT and passed.