I have a 91 camaro Z28 and I was driving it one day, stopped at a friends house and when I went to start it, It wouldn't start right then once it started it have a very rough idle, and when I would go to give it gas it seems as though i lose power and it acts like it sounds like its missing. I got a ODB 1 thing to check the computer because the check engine light would come on and off, but it would never stay on. The codes that came up were: 12, 44, and 45. Does anybody have any idea what these codes mean, and or what is wrong with it and how to fix it. I'm doing a motor swap so there will be a different motor going in it. The motor that is in it now have about 2500- 3000 miles on it, so it's relatively new and I would like to find out whats wrong with it so that on my next project I can put that motor in an old truck and not have to worry about the motor being shot. It is a 305 TPI motor if that helps.
Thanks

 

GM Check Engine light Codes without a Scan Tool

here is a list of all the codes.

 

thanks man... that helped a lot