[GhostDakota]

Originally Posted by BigAls87Z28

Okay, went back and reread some of the stuff. You pulled the AIR stuff apart to get the plugs, so that makes sense as to why your are missing it in that picture. I hope that when you put it all back together that you used some sort of hi-temp gasket material so that you don't have leaks that could cause other problems on top of the problems you already have.

So you replaced the plugs and then all these problems came up, or did you have a problem then replace the plugs?
Have you checked the coil?
If he's misfiring like an "AK47", that will cause the O2 codes to trip. O2's are probably covered in a lot of fuel, and they looooove that.

Check the coils, might have a problem there. Swap some of them around, see if that changes the rate or the pitch of the misfires. You might be looking at one, or more, new coils.

The P0420 code started over a year ago (August 2011 or so). No negative/adverse driving issues were occurring at the time.

The misfire started when I returned from the Hamptons several months ago (July 2012?). No high RPM driving to/from the Hamptons, just highway through some ****** parkways (Belt, LI, etc.).

Because of the misfire I:

-Replaced the plugs
-Replaced the wires
-Swapped coils around (Problem stayed on #5 & #7)
-Removed #5 injector, replaced with a known working injector
-Checked cats using infrared thermometer & tap test:
----Driver side 450*/400*, no rattling
----Pass. side 350*/300*, no rattling

GOtta run, post more later.