The first problem is when I'm driving kind of fast the check engine light will come on and then shuts off when i slow down, the second problem is when the car is at operating temperature and has just been started up the engine will stall when put in reverse or drive, lastly my other problem is that when it is in park and idling the rpms will increase from 1200 to a little under 2000 rpms and bounce around between that range and it sounds like the car is backfiring or misfiring i don't know, anyways info about the car its a 1987 firebird that was originaly a V6 but somebody else swapped a 350 into it, its got a 700r4, its tpi and the timing is set at 6 degrees BTDC.

 

You need to retrieve the trouble code(s) from the computer. Even though the light goes out, the codes are stored in the computer for 50 starts or until cleared.

If you don't have access to a scan tool, the process is described in the FAQ linked from the thirdgen.org homepage.

 

so i have code 21 High voltage at throttle positon sensor, and code 42 Fault at electronic spark timing circuit OR Fault at direct ignition system OR Fault at fuel cutoff relay circuit, how do i go about fixing these problems?