My wifes Cobalt is on the fritz again! Its an 06', 2.2 with 125k miles. I have been experiencing an inconsistent misfire, PO 301 is the code that sets repeatedly. Sometimes it runs fine and there is no problem. At times it feels like a cyl. is randomly dropping in and out with some stumbling, other times it feels like there's a completely dead cylinder and if I run it hard, the check engine light will flash.
It has gotten to the point its not safe to drive because the engine will shut off going down the road or at an intersection.
I replaced the spark plugs around 100k miles and have recently swapped them around to see if the misfire moved cylinders, it didnt...
I was going to try swapping coils around but dont know much about these engines...
Not exactly sure what my next step should be?
Any help would be greatly appreciated and as always, Thanks in advance!