I have a 94 camaro with a motor out of a 95 impala ss, that was hand built with a lot of goodies in it. I had opti spark problems but msd solved the problem now Im having problems checking the codes on my car why is this happening.

 

What are you using to check the codes? Need more info.

If you are trying to flash them on the dash, it won't work. You need a scanner.

 

I understand that i need a scanner but is there any particular type of scanner that I need to use, because I have a 94 Camaro with a 96 computer and the computer has been programmed for the mods on the engine.

 

Lets make sure this info is accurate:

You have a 94 F-Body chassis.
You have a 95 B-Body LT1 engine
Tou have a 96 ????? PCM (probably would have been a good idea to include this in the first post)

If that is correct:

The 94 chassis would have a 12-pin OBD-I ALDL connector. The 96 PCM (whatever its out of) would be OBD-II. Have you wired the PCM correctly to a 16-pin OBD-II ALDL connector? Are you trying to scan it with an OBD-II scanner?