Quote Originally Posted by ViperGeorge View Post
As AZ says on a Gen 5 you will need the dealer to do a throttle relearn if you change the throttle bodies. I would agree with others though that it seems unlikely this is the problem. Not impossible I guess, just unlikely.

There are several things that might cause the problem. Check connections to the PCM and make sure they are tight. Do you have headers? If so and if your wiring harness is not properly insulated you could have melted wires internally causing an intermittent problem. The outside of the harness typically looks ok but wires on the inside could be melted. I have first hand experience with this. You can start the car and then move the harness around if you have a melted shorting wire it is possible that the movement will trigger the issue. Also check all grounds.

Good luck.
Thanks for the suggestion.

I do not have headers. I've kept a close eye on this area because I had seen a few issues. I almost always open my hood when i get back from a hard or longer trip to try and prevent this. I will likely build a heat shield for this area as well.