I got the half engine light today with cc id 029 and obd reader for my phone shows pending fault codes p0304 and p0303. I just cleaned my intake valves and replaced the spark plugs a few weeks ago.

some history: the HPFP was replaced in 2015 at 67k miles and the car now was 84k. right before I had the HPFP replaced I replaced 2 coils cause I thought they were the issue.

anyway, I wont look under the hood till tomorrow cause this happened tonight. I'm thinking it could be the diverter valve or a coil, and not the hpfp cause it was replaced not long ago. but would a bad coil cause a misfire in a second cylinder? cause I don't see 2 coils going bad at the same time. I did have a pending p0304 fault before I changed the spark plugs a few weeks ago. but the car was running fine then.

 

I fixed it. cylinder 3 or 4 coil went bad, and that was one of the new coils. delphi is the brand.

I took out 2 plugs and they had oil on them on bottom side and they are 1 month old. is that normal? maybe I should get a compression tester.

 

If the valve cover gasket is leaking oil around the spark plug hole areas, that oil will drop down onto the plug as you remove it. Did you look into the spark plug holes before removing the spark plugs?

 

I replaced the valve cover gaskets a few months ago. there was a nasty leak at that time. there doesn't appear to be any leaks now.