02C230C Lebanon

A month ago my 2002 2.3L C230 Kompressor coupe started having a rough idle from time to time, and now more frequently. My micro Bluetooth scanner gave me code P0304 which is misfire on cylinder 4. Not knowing which one is cylinder 4, I removed the red cover and swapped all 4 coils, cleared the code, drove the car (still had a rough idle), scanned, still have the same code from cylinder 4. Spark plugs are fairly new under 10'000 Km. Should I try swapping them too? And which one is cylinder 4? What else could the problem be?

capt_paul

I have the same code...from researching, I found that it is ignition and/or fuel related. Since you swapped the coils and changed the plugs, I would suspect a bad fuel injector and possibly the fuel filter.

I will replacing all 4 plugs, and the 4 injectors this weekend on my 2005 C230