I have a buddy with a 2000 Trans Am with a po300 code in the pcm. He has a really bad power loss and it is missing. I think there is a ticking noise in the passenger side injector rail? Replaced two coils, and plugs. Same problem is still happening.

 

go to autotap.com and find out what exactly the code is

 

I'm having the same problem but it only missfires bad when I have HPP3 program, and when its not programed it just runs real ruff with a loss of power, where is the ignition modual located, and how would you cheack it?