misfiring still please help

hey guys I got a 96 gsr with 170000 miles on it and just got a rebuild done because everything was due for maintance and because I had two bent valves. so we got that problem fix and the cel is still reading misfire cylinders 1&2 and random misfire. we checked possibly everything that can cause a misfire to occur. the engine itself is not missing I don't hear or see any abnormal behavior from the engine. also the car is running rich too, put new plugs in and turned it black quick. vaccum is good, fuel pressure regulator is good, fuel is good, map, iacv, crank sensor, timing, dizzy all oem, all of them checked out am I missing something? also I have a dented header dc 4-1 will that cause a cel? I need help and it's driving me insane. any suggestion/idea would be much appreciated

thanks

try this get a noid light and check if your injectors wire harness are working if everything checks out try replacing your spark plug wires your wires might be bad

i bet you this is a 60 dollar fix bank 1 02 sensor gone bad will trip the cel with an in-audible misfire itll kill plugs and eventually your catalytic converter if your running too rich for too long if its not that i honestly dont know what to tell you lol