Ok the gf's 01 v70 2.4 N/A is have a DTC and pending DTC P0304 Cyl 4 Miss. I did the plugs not to long ago maybe a month ago so i swapped the coil with another cylinder and the code came back as cyl 4 miss. I checked the PCV system and have vacuum from the oil fill cap. So i pulled the plugs out and cyl 4 looked different. It had a flaky deposit on the center electrode and oil on the threads. I heard alot about the oil filler cap gasket but theirs no oil on the cover. Need some suggestions on where to go next.

Ed