I have a 2004 get coupe, we swapped everything it runs and drive fine just as it should, but some times when you go to start the car it wont fire up. It throws a code sometimes when this happens saying ecu to ignition communication error.
other times it starts right up and drives perfect. Does anyone know why it just doesnt start like this every once in a while?

 

Exactly what codes is it throwing, it sounds like you have an intermittent short and I would first verify that the ECM and BCM grounds are tight, those are the ones behind the console and behind the stereo.