my 06 cts just threw the engine light today with codes P0300 for misfire in cylinder 2,4 and 6. Anyone recommend change of spark plug and/or coils to fix? I might as well do them all if i am going to do any... car has 43k miles
I had EXACTLY the same issue with 2,4,6 and checked the oil and was low by 3 quarts in less than 500 miles. Refilled the oil and engine went back to smooth operation! Problem not solved but at least narrowed down to the cause... I have not rechecked the cylinders but plan to soon(I'm not sure if codes will auto reset or if they are stored until computer reset, so even a code recheck might not rule out the cylinder problem if it was previous to adding oil??).