Everyone,

I am a much long time reader, and recently a new member. I have a friend with a GMC having some trouble passing the sniffer test.

The truck is a 94 GMC 4.3 Vortec has over 155K, and is blowing high HC at idle. It has New EGR,plugs .045,wires,cap,rotor,PCV,Convertor,etc.

Im blowing 410 HC at idle, and max aloud is 220. The idle was around 650, but I slightly raised it to help slightly.

ANy tips, suggestions from anyone, It really need to pass this truck, its his only vehicle, and is currently not allowed on the roads. He needs it to survive until Fall when he will be purchasing a FORD

Truck runs great otherwise, just high HC at idle, not at Load ???

Is there any trick ways to pass a sniffer test ?? Do those fuel additives really work??


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2001 XLT

 

go to a place in the middle of nowehre and offer a little extra $$$.

 

STATE CONTROLLED

 

Has he ever replaced the O2 sensors? That would be my first guess.

 

change the oil just before going to have it tested. this will drasticly lower the HC emissions .

 

I've always heard to take your truck out and run it for a while before you test it. Have the motor good and hot, Rich.