GreatWhiteHype01

I have had this trouble for quite some time now. It only happens after the engine has been running for a long period of time. It usually happens on the highway. The engine will begin a heavy misfire. I think it is fuel related. It used to misfire heavily but since I installed the MSD coils it has gone to more of a fuel related misfire. It's almost like it just starts dumping too much fuel. I get a P0300 multiple cylinder misfire immediately. Then comes the P1153 and P1155, these show Manufacturer Fuel Air Metering Device. I also get the low voltage o2 sensor code. I have new Accel 300+ Wires, New ACDelco Irridium plugs, New MSD Coils, & New Bosch o2 sensors. My mind is boggled because I went to school for this stuff. I do however have some slight meltage to the o2 sensor extension plug but the wires are not damaged, just the plastic part of the plug that the the o2 wire plugs into. This is due to the harness being forced against the header by the wind from the highway. Can anyone help?

If it makes any difference I also have the following bolt-ons:

SLP Ram Air
Smooth Bellows
Throttle Body Coolant By-Pass
SLP Long Tube Stainless Headers
3" True Duals No Cats, No Mufflers
Diodes COnnected to the rear o2's that send the correct mv to pcm
Custom PCM Tune
2600 Trailblazer Stall
Vette Servo
3.73 Auburn Posi Unit

Thanks.