I should also add that the pressure didn't change whether it was WOT or when turned off the ignition switch.
Once i turned it off, tt pretty well dropped the needle to 45-46 and it stayed there until i took the gauge off.

 

And a bad/burned out or shorted O2 sensor could cause 2 specific injector circuit failures when there doesn't appear to be a failure or short in the wiring?
Does it mess with the way the PCM handles the pulse to the injector or something like that?

 

The PCM expects to see voltage on the return wires, if it doesn't, it will whine. (injectors) So far as I know, there is no commonality between the circuits.... and if there were, I would expect to see more of the injectors having issues. (they all get power from the same place, PCM controls ground side of the circuit.)

Does the engine run crappy immediately at cold start? Or does it take a minute or two before it starts screwing up?

 

It's immediate and consistent every time, no matter what i've done.
It will run, poorly.
I'm not wanting to throw away years and years of meticulous care, pints of blood, and gallons of sweat by burning a hole in a cylinder.

 

Hhhhmmmm...... Well, you have done pretty much all the troubleshooting possible. It isn't the injectors, it isn't the pcm, fuel pressure is indeed good..... the pcm is at least trying to control the injectors..... and I think the codes are actually whining about the control circuit..... that leaves the wiring...... Yeah, I know, it'll fire the noid light, but, the noid light just doesn't take much power to light up. The injectors are a bit of a different story..... that, and the 8.0 pcm software can be a bit weird.... I had a dead miss on a cylinder (plug wire burnt in half) that I could feel, but, the PCM never set a code for it.....

About the only other thing I can think of, would be putting a load on the circuit, and see if it still works..... Might take some creative fabrication.... but, using your 'spare' injectors might work.....

Something else to consider is, they are false codes, and the pcm is just guessing at what is really wrong.......

Do you have a scanner that will read live data?

 

I have torque pro, a good OBD2 bluetooth adapter and a multimeter. It doesn't see everything though.
I had already watched the 02 sensors, timing advance, and other basic things with it.
It's also what I'm getting the codes from.

 

Have a look at coolant temp, and TPS. See what they think. Also check your misfire counters, if you can..... see if it is just those two cylinders, or are you getting misfires elsewhere as well.

 

Could a mechanical issue like timing or worn camshaft potentially cause this?
It came on without warning and the truck was running great the last time it ran.

 

Anything is possible. Maybe do a compression check on the two cylinders in question, see what ya get.

 

I will do a test and watch all cylinders. When I looked last only 5 and 7 were misfiring but the very first set of codes had cylinder 8 in there too.
Now only 5 and 7 are misfiring, which is why I've gone after all the wiring.
I might go put a squirt of oil down 5 and 7 tonight and try running it longer tomorrow morning to see how the rest of them do.