Still having misfires on bank 2, need some help

[AmunRoo]

So, my bank 2 Cat died and caused a whole mess of issues. Misfires galore on 2, 4, 6 and 8. So had the cats replaced and then replaced plugs and wires. Cleared up for a bit and then began having misfires on bank 2 again. Did a smoke test, because i figured I had air intrusion and found the oil filler neck to have a massive smoke leak. Got rid of the filler neck and bought a new oil cap to place directly on the valve cover. Cleared up and then it came back again. Fuel trims showing lean on bank 2. Replaced all O2 sensors. It cleared up but came back, again. Smoke tested once more and no leaks. So I'm not getting and intrusion of air. Fuel pressure is at 58ish psi, oil pressure never drops below 11 psi, I swapped coil packs, wires and plugs. Still happening. The truck will run fine and it'll come out of nowhere. Sometimes it clears up and others, I can drive the truck. I've also sprayed carb cleaner under the intake, throttle body, valve cover and upper intake plenum. Wiring is intact. Not sure where else to look. I need some help here, fellas. Last option is to take it in to a shop. Normally, I can figure these things out, but this one has me stumped. Any help is greatly appreciated!

 

[OR VietVet]

Recently, a member had an entire bank giving him problems like this and turned out being the ground(s) for the ignition coils or fuel injectors, IIRR...If I am wrong about that thread I hope someone posts and corrects me. Think it was at back of head.

 

[rcsnipe2000]

my 07 escalade did this. it was the underhood fuse block. power comes from there and supplies all the injectors and coils with power on that bank. the other side has its own power line from the fuse block.

easiest way to test it is with a power prob. you can do it right at the injector and it will power them all up. do it while engine is running and it will run good when you add the power to the wire. the whole side of the engine will come to life.

internal short in the under hood fuse block.

popped it out, popped a used one in from the parts yard and good to go.

hope that helps.

 

[AmunRoo]

That helps tremendously! You say the ground is at the black of the head? As for the bad fuse block, will it be in the fuse box? Im new to the truck platform. Its my first big truck.

 

[Dustin Jackson]

The oil filler neck is a killer one, once it has a leak like that it is basically sucking dirt into the oil the entire time the motor runs