Horrible backfires 97 lt1
 

hey guys, I have a 94 lt1 in an s10 but I am currently working on my friends 97 lt1. The car was running fine until it blew a head gasket. We replaced the head gasket hooked all the sensors back up and now the car starts and idles but has a bad backfire. We got a scanner and it was throwing codes for the maf, the o2 sensor on passenger side and the coolant temp sensor. we fixed it and the car is no longer throwing codes but still back firing and from what i can tell seems to be running rich. We are about to throw new plugs, wires, and a crank position sensor on. the coil is good. What else could it be? I do not think it is not the opti because it was fine before it was parked to be worked on.

Did you get the head checked before reinstalling? And did you hook the wires up to the correct cylinders?

yes the wires are all hooked up right and a machine shop had checked the head.