I started getting a misfire code, P0308, on my expedition these last few weeks. It only happens under hard acceleration when cold so I am assuming it's a weak coil. Is the number 8 cylinder in the back on the drivers side, just looking for clarification.
Changed the plug today and it seems to have fixed the problem. I was really shocked as to how bad the one I took out was worn. If they are all that bad maybe I should change them all and hope I dont break any.