Sorry this might get long
12' F350 6.2
It started off with an extended crank issue, read most of the threads on here about that issue.
It worsened to it would barely run, unless i got a lucky rev, and it would take off, and I limped it back to our shop.

Not having endless diag capabilities or time, being im the mechanic and do other on site work, i decided to replace the fuel pump due to it probably needing a fuel filter anyways @ 171k and hoped it would solve the extended crank issue

(btw no engine codes had ever shown up at this point)

I replace the fuel pump, and it now immediately starts, but still has the stumble low idle issue.
I unmount the pump control module and tap it against the framr trying to loosen dirt in the elec connector, while looking for the test procedure online, i read about the exact scenario, and someone Unplugging the MAF sensor and it going away. This leads the truck to not start at all
​​​​So I remount the module and plug the maf back in
It takes awhile but restarts and the stumbling is gone.

Now on my way back from the GFs house it gets so bad I barely make it into the local oreillys, i take a gamble and replace the MAF sensor, since it still has not given ANY check engine lights or codes

Truck roars to life like a brand new truck, only 30 mins later to start acting exactly the same way, BUT NOW we have codes, unfortunately i didnt save them all, but oddly the truck was showing Lean And Rich at the same time on both banks, and all O2 sensors

Here are the permanent codes that remain, the truck will fire immediately still, but after time starts stumbling, hesitating, and even stalls out.

Does anyone have any clue what might be happening?
I've checked vac lines all good (except broken connector at 4wd hub that i repaired), new MAF, New Pump.

We have a HF ZR13s scanner i can use, or i have a fancier unit at home, that is so complicated I set it down and never picked it back up lol
I did pay for forscan, but my dongle was too old it said, and just havent had a chance to pick up a new one

What should I be looking for to solve this, im about to convince the boss to send it off to ford if I cant fix it soon

P0171 system too lean (bank 1)
P0174 system too lean (bank 2)
P2198 O2 stuck rich bank 2 sensor 1
P2196 O2 stuck rich bank 1 sensor 1
P0308 Cyl 8 misfire

 

I would suggest that you replace both front O2 sensors and see if that clears those codes up - do this before moving on, as it's causing ALL your cylinders to go haywire, not just cylinder 8. It may or may not help the misfire code too.

As for cylinder 8 misfire, inspect the plug. If it's white, it's running lean and not getting enough fuel, if it's black/dark it's running rich and getting too much fuel, if it is just WET then it's not firing at all. If you have access to one, it may not hurt to slip a bore scope in there and take a peak, make sure the cylinder itself is in good shape. I would suggest replacing the spark plug first (and if you've never done them do them all) and see if that helps, if not you may need a new injector or coil pack, and I offhand don't know how to test those.

 

Have you thought about switching out the computer? With all those codes at nce it is possible that the board could be bad. Perhaps cracked or shorted and is making it act like it is. Might be worth a try if you have one handy. Maybe some wirng may of got hot and has melted causing a short? Baffling and annoying I'm sure.