The Nissan Path

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?

It sounds like you have bigger issues that just a bad coil. There have been a number of issues that cause oil burning on these engines. One is when the power valve screws fall out and land in the combustion chamber and cause detrimental damage to the engine. Another is the oil control rings get stuck in the piston landings and oil gets into the combustion chamber. Of course, a ring could fail on its own. I would recommend you do a combustion test and cylinder leakdown test of the engine to try and figure out where the oil is coming from.