TechFan
Junior Member
Ok so for starts im a comm small engine tech and familiar with in depth efi engine diag but dont have access to diag software for this vehicle. having said that, i also know how stupid it is to "shotgun approach" a diag but since that parts were cheap i did exactly that. My wife has a 2010 cobalt 2.2l. it is throwing a cyl 4 misfire code and its completely iso'd to that cyl (at least for now). I first swapped the ign coil with another cyl and it still threw a 4 code. Then i went ahead and did the service parts i had yet to do that might affect run so i did fuel filter, plugs and even ran some injector cleaner thru system. Still not helping i went a little deeper and actually replaced the #4 injector.. surprise surprise still didnt help. then as a last ditch effort i thought poss so issue in connector to coil so replaced it. I have noticed on posts for other years people talk about ground issues but im not aware if they have sep ones for each cyl bc if not i would guess it would cause random misses and not always the 4. This issue has been going for about 4 months so my thinking remained at something that would be iso'd to the 4 but since im not familiar w this vehicle that way i could be wrong there too. Any help from someone experienced with this car would be greatly appreciated. Thanks