Symptoms: loping (limp mode) idle at warm start (completely fine cold starting). Power loss on hills. Intermitent power loss while accelerating. Edge programmer is showing appropriate RPM reading but the motor is obviously bogging and struggling. Shakes the entire truck while it recovers to normal idle. Drops as lows as 400 rpms when bogging at idle but never kills the truck. Sounds like it's missing or a bank isn't firing when it's acting up bad. Sometimes it'll run great for a mile or two before acting up again. This all started randomly after two hours into a road trip doing 70mph on flat highway.

What I've done: replaced fuel pump, fuel filter, air filter, checked for turbo and exhaust leaks and cleaned tanks and mesh filters in the tanks. I'm an idiot and didn't think to check for bad codes till after I did all that. Auto zone's reader said it was good to go. Lies. My edge programmer threw a bad ECM code (P0603). I have only ever used the programmer to set shift points for my transmission. So I returned everything to stock and the problem still persists.

Ive spoken to a dozen mechanics almost all of them have differing opinions on the matter. Thoughts from these mechanics are a physically broken ECM that only starts acting up when the motor heats it up. A corrupted ECM that needs to be flashed/replaced. The ECM is fine and the code is the sign of a larger issue like injector wiring. Bad injectors. Bad injector controller on the HPOP. The two shops I've had it at couldn't have had differing opinions and were dead set on replacing completely different parts. I know owning a diesel is like throwing cash into a fire which is fine because I use and love this truck but I'm definetly done throwing money at this particular problem with "best-guesses". Thoughts please

 

Quit throwing parts at it and put a REAL scanner on it. with a COMPETENT person looking at it