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cw6292 · 08-11-2008, 09:45 AM

My truck idles rough and blows black smoke which smells like gas when 1st started. The error codes show system too rich on both banks. It also is giving improper switching of the O2 sensors pre-converter. The O2 sensors don't send any info back until they get up to temp, I thought? I have changed the plugs, wires and distrubtor and still the same. I am leaning towards the MAF and/or MAP sensors, but would like to hear someone elses opinion as these are not cheapest things to replace. Easy to get to, but expensive. My thought is the trouble is before compression not after. Any advise will be much appreciated!

08-11-2008, 09:45 AM	#1 (permalink)
cw6292 Registered User Join Date: Aug 2008 Posts: 1 OS: xp	97 chevy silverado 5.7l 4x4 My truck idles rough and blows black smoke which smells like gas when 1st started. The error codes show system too rich on both banks. It also is giving improper switching of the O2 sensors pre-converter. The O2 sensors don't send any info back until they get up to temp, I thought? I have changed the plugs, wires and distrubtor and still the same. I am leaning towards the MAF and/or MAP sensors, but would like to hear someone elses opinion as these are not cheapest things to replace. Easy to get to, but expensive. My thought is the trouble is before compression not after. Any advise will be much appreciated!