I am getting a code 18 on my 1995 z28. The car is running very rich, BLM on right side is at 160. The O2 sensor on right is jumping around like it should and the left O2 is hanging around .250, after warm up. I thought the drivers O2 was bad, so I changed it with same results. The car runs great when cold and stumbles on take off when warmed up. If I get on it a little harder it clears up pretty good. Now I know the code 18 is something with the injection system, has anyone else experienced this problem before? Oh, car has a CAI, headers, and flowmaster exhaust, that's all.

 

You should be electrically checking the injectors and their circuits. That's what code 18 is about.

 

Leaky injector wouldn't set that code off would it?

 

The PCM would have no clue that an injector is leaking. Check the electrical side of things......as Rob suggested.

 

Key on, check for 12V on the pink wire at each injector. Then check the resistance of each injector (harness connector unplugged). Should be 12-15 ohms. Finally, us a 'noid light to verify the PCM is providing the ground to fire each injector.