Sorry if I suck at explaining my issue...I am new to the forum and new to cars with computers. I have a 1993 z28 with the stock lt1. It has about 193,XXX miles with no rebuild. The engine misses very badly and makes popping noises. The problem is not as bad when the engine is cold. This issue has happened before and it seemed the problem was the water pump was leaking in the optispark. The optispark and water pump were replaced and the problem was corrected until now. It seems like the same problem but this time it runs so crappy that the car will barely move. Here is the weird part...If you rev the engine it will only rev to around 2000 rpm then pop one good time then the SES idiot light comes on and the engine runs fine. I have not got a chance to take it to the shop to run the code yet(auto zone and those places only run OBDII codes). If anyone has had this problem and knows how to fix it or knows how I can run it in whatever mode its in when the ses light is on all the time(until I get a chance to rebuild the engine completely) PLEASE HELP. Thanks.

 

Also, the cats were cut off and side may be leaking. I am not sure if that could be involved in this.

 

try replacing the plugs and wires.also the popping happens when having no cats