I have a 95 z28 fresh rebuild lt4cam kit headers nothing to fancy yet replaced all major engine parts. My brother one night right after we got the motor in he went on a drunken bender fired it up straight headers was idling nice no probs so he decides to romp on it 6 times or so the last time it back fired through the intake , since then it runs rough and bucks and chugs, just curious as to what kind of things may have happened when it backfired

 

Could have damaged:
-MAP sensor
-throttle blades
-IAT sensor
-MAF sensor
-Opti vent lines/backflow preventer

Could have dislodged vacuum lines or the rubber 90* air inlet elbow

All need to be checked. Is the SES light on? I would scan it for codes anyway.

 

i have scanned it for codes and have none. i was wondering if it could be a bad tune on the pcm. i have been messing with it for close to 8 mths and am so fed up and frustrated..the only othertghing i have really done is removed the exhaust pump from the motor but stillno lite. the part thats getting me the most is i have no lite coming on even though its runing bad enough to buck and chug even down the highway

 

Running it with open headers probably caused it to run very rich, as backwash of air into the collectors made the O2 sensors read lean, and had the PCM adding too much fuel. That could explain the backfire,

Was it tuned for the cam?

What did you use to scan it? Scanning for codes isn't going to tell you if there are vacuum leaks, the elbow blown off the throttle body, damaged TB blades or if the backfire damaged the Opti case (no codes for the high voltage section (cap/rotor). Did you check all those?