At idle my engine is running rough. it has only 28k on it. The only mod is a K&N air fliter. I have checked nothing so far. My question is what are the common causes of these engines running rough. I thought I would ask before troubleshooting. I also think that 28K is way too soon for any problems.

 

You haven't washed your engine compartment have you???? This is the kiss of death for the 5.4s and 4.6s with the Coil On Plug (COP) configuration.

Sidewinder

 

No I havent washed it. but I will check for any moisture.