I had a misfire not too long ago and had it checked at autozone, they put a computer on it and said I had a misfire in cylinder 1. And it was one of three things, the coil, spark plug, or the injector...I replaced them all and still had the misfire, had me stumped...until I pulled my intake off because I saw oil on top of my valve cover (blow by) and I saw that I had a puddle of oil in my throttle body where the intake plugs in. So then I pulled my air filter out and it was covered in oil...so my guess is that all that (blow by) is fowling my spark plug over and over..meaning its either my valve seals or my ****in piston rings in cylinder 1. So it looks like im pulling my engine again just to pull that damn head off.
Funny thing is that a friend of mine recently told me that he took his heads to the same shop I did to have my heads rebuilt a few years ago and the mechanic didnt replace his valve seals..my buddy ended up figuring this out when his engine started doing the same **** mines doing now and when he pulled it apart, he took the heads off and took them some where else and told the mechanic that his new valve seals should have been orange, turns out they were black, basically meaning that the other mechanic (the one I went too also) didnt put the new valve seals in. Im guessing that ******* mechanic didnt replace my valve seals either. Because before I rebuilt the engine it had some blow by then too.
This completely ruined my week.