I have an 02 pathy with 129k. 3.5L. I got the check engine light, and the engine is stuttering at idle. It also bucks a little when I get it into overdrive. I ran the code, and its misfiring at cylinder 5. I replaced the spark plug, and the old one was covered in oil where ignition occurs. It doesn't miss as much with a fresh plug.
Should I bother replacing the ignition coil? Or is my problem with the oil leaking into the cylinder?