So I was towing a load..and the check engine flashed..kinda hesitated then ran good..did it few miles down the road a few more times..then back to normal..left it idle while I picked up another sled...driving away then just went into stupid mode!! Felt like half bank went down. Can barely run but will start. I did the fiddy cent mod a couple years ago and it kinda presented exactly the same. I disconnected the ICP with no change..I did develop a leak around the IPR over the last week..not sure if related or a co-inkidink..I did rebuild it leak a year ago..did a good job eh'!
Thinking it was the wiring harness again. I removed it from the drivers side to see if there was a short, rubbing (next day, cold eng.) I didn't see any signs of rubbing. Put it all back together and it fired up..runs fine.. Now I'm afraid to drive it.

What ya think?

 

Sounds like a UVCH issue (burnt pin, loose connector, possible bad injector solenoid) if it felt like one bank kept running, it still started, and it felt like the engine was going to rattle the mirrors off the truck.

 

This is screaming UVCH. After verifying that's it (using the UVCH link in my signature), I'd get a pair of new UVCHs or a pair of those valve covers with the UVCH hardwired in.

 

Ok, I guess that's what I'm replacing..My poor knuckles!