completly lost

[M4K3L4]

I have a 96 ecsb with a 5.7l, haven't had the truck long and my problem started as just a little bit of a rough idle and would only do it from time to time. As it progressed the check engine light would occasionally come on. I took it to a friend who scanned it and it came back as a random misfire. I changed fuel filter, plugs, wires, cap, rotor, coil, knock sensor all with no improvement. We scanned it today and it said maf sensor failure, replaced that and still nothing. The problem has progressed to were the rough idle continues thru a little less than half throttle, sputters and misses. Any thoughts/ help would be appreciated.

[silverado94]

that sounds like your o2 sensor http://www.ehow.com/facts_4899182_sy...n-sensor_.html

[Boog]

Check your fuel pressure first thing then go from there.

[bighaas79]

codes are one thing but what about datastreams? should be able to look at misfire counters and see what cylinders are reporting the misfires. O2 readings and fuel trim info would be helpful.

[M4K3L4]

Thanks for the hints so far. Ill have to ask about the o2 and fuel. last time my friend hooked it up it was showing #2 cylinder as the problem, 1300+ missfire's while it was hooked up. Hes thinking intake leak. I haven't had much time to dig into it.