I have a p0301. Have changed the spark plugs and rotated coils to rule them out. on 2009 Pontiac G6

What should I look at next?

by in Hampton, GA on January 11, 2014
5 answers 2 comments
ANSWER by on January 11, 2014
Check for vacuum leak and injector pulse. Plug wet when removed? If so, check compression. Seems we have quite a following here, hope you get it fixed!
ANSWER by on January 11, 2014
I'd start looking at the injector or injector wire harness
COMMENT by on January 11, 2014
Boy i sure wish i had thought of THAT!!! Do you know what injector pulse is?
ANSWER by on January 11, 2014
When does the misfire occur? At idle? Under a load? Or all of the time? Is it constant or does it come and go?
ANSWER by on January 11, 2014
Try the intake induction service, Per GM Bulletin.
ANSWER by on January 11, 2014
Just rotating the coils will not show up a miss fire, as it will just move to another cylinder. Try disconnecting one coil at a time when engine is running. If when a certain coil is disconnect there is no difference in engine missing, you have found a bad coil.
COMMENT by on January 11, 2014
It will change the misfire code if coil is defective and switched to another cylinder!