I see the list of parts replaced which usually eliminates the hard parts - and the common causes of these codes so maybe we can start outside the box this time. I would recommend however putting a fuel gauge on the truck and monitoring the low pressure supply system pressure when the low power symptoms occur. This is a MUST. Pressure should be 3-8 PSI.
After replacing the HPOP did you carry out the fuel volume control valve and fuel pressure control valve adaptive learning parameter reset? This shouldn't cause this concern but it cannot be ruled out.
The diagnostics for this pay a lot of attention to the pressure/volume control solenoids and circuits. Test the solenoids resistance cold and hot - they should measure between 1.5 Ohm - 8 Ohm. I would also recommend load testing the circuits from the PCM to the 4-pin connector near the GPCM.
Verify that the pump has a good VPWR circuit, meaning a solid 12V supply to both green/white wires at the HPFP harness connector - LOAD TEST the circuit and perform a voltage drop test and wiggle the harness while doing so. The VPWR circuit for the HPOP comes from fuse F74 in the battery junction box and it feeds the HPOP, Fan clutch, EGR throttle plate, turbocharger actuator, GPCM, EGR valve and the MAF sensor - any of which could in theory pull the circuit down. Do not forget to remove fuse F74 and look at it closely for fretting (burnt marks) that would indicate poor terminal fitment. I HAVE seen that fuse loose in the fuse block and it drove me nuts to say the least.
Good luck!
After replacing the HPOP did you carry out the fuel volume control valve and fuel pressure control valve adaptive learning parameter reset? This shouldn't cause this concern but it cannot be ruled out.
The diagnostics for this pay a lot of attention to the pressure/volume control solenoids and circuits. Test the solenoids resistance cold and hot - they should measure between 1.5 Ohm - 8 Ohm. I would also recommend load testing the circuits from the PCM to the 4-pin connector near the GPCM.
Verify that the pump has a good VPWR circuit, meaning a solid 12V supply to both green/white wires at the HPFP harness connector - LOAD TEST the circuit and perform a voltage drop test and wiggle the harness while doing so. The VPWR circuit for the HPOP comes from fuse F74 in the battery junction box and it feeds the HPOP, Fan clutch, EGR throttle plate, turbocharger actuator, GPCM, EGR valve and the MAF sensor - any of which could in theory pull the circuit down. Do not forget to remove fuse F74 and look at it closely for fretting (burnt marks) that would indicate poor terminal fitment. I HAVE seen that fuse loose in the fuse block and it drove me nuts to say the least.
Good luck!