Ok, back to the beginning.
Before replacing the head gasket, I poured a bottle of Bars Leaks head gasket repair into the radiator, 33oz. I could not keep the car running long enough per directions. The coolant was disappearing as fast as I filled it.
I then started the tear down and when I got to the head gasket, there was about 1/2" of material missing between #4 and #6. I put this all together and started the car. It had a very rough idle. I then went through the troubleshooting process of checking the coil pack, injectors, replaced PCV, plugs wires, used noid light on injector, MAP, MAF, Idle control needle, EGR, found no vaccuum leaks.
I assumed it was either a warped head or valve issue. I installed a new head, gasket, and bolts yesterday. It started great and no misfire until a minute or so later. It started sounding slightly random, then became very steady on the misfire.
When the head was off, I inspected the cylinder and appears fine. The old head has very black exhaust valve on #4, but the other 2 are white.
The other issue that started right after replacing the head gasket was really low oil pressure. It does not register over 40.
When I accelerate, the misfire disappears and while driving, I do not notice any power loss or misfire at all, until it drops back to an idle.
I had this at the dealer prior to swapping out the head for diagnostics, and they informed me that #4 was at 90 on a compression check.
What am I overlooking?