I have a 98 Sunfire 2.4l with a misfire code 306 all cylinders are doing it what part would need replacement?

Question

I have a 98 Sunfire 2.4l with a misfire code 306 all cylinders are doing it what part would need replacement?

Answer 1

Your 4-cylinder engine is misfiring on cylinder #6 (P0306 os a Cylinder #6 msifire).  That is interesting.

If all the cylinders are misfiring then you should be getting a P0300 Random Cylinder Misfire Code accompanied by P0301, P0302, P0303 and P0304.  A real scan tool (not some cheap parts store code reader) can watch the misfires in real time and tell you how many are current and how many are in history (one of the few things GM got right - Ford won't even acknowledge that their cars misfire, let alone count them for you).  

As always when dealing with a misfire you should start by replacing the spark plugs.  In this car also replace the spark plug boots which are part of that wierd plastic cover on top of the valve cover as these can go bad.  Clear the codes.  If the misfire returns then its something else (injectors, poor compression, coil, etc.) but at least you got some good routine maintenance out of the way and have a solid baseline to start with.

Answer 2

  The coil pack and they arn't cheep.