Codes:
P1744
P0443
P0174
P1131
P1151
P0171

I’ve checked for vacuum leaks, replaced the EGR valve, (it was letting smoke out of the valve during the smoke test) and have checked my fuel pressure(33+ while running.) The truck is acting like it is running out of gas after three-quarter throttle, will stall and backfire when it is cold from a stop, and will decelerate if it downshifts to pass/maintain speed.

Retired U-haul box truck, 7.5 mass air, 155K.

I don’t want to start throwing parts at this before I get an idea what the problem is.

the torque converter solenoid issue I’m aware of, and am dealing with that as soon as the motor is squared away.

New codes after codes cleared while changing battery

P0401
P0171
P0174

 

Idle fuel pressure should be 30-35 PSI. Under load the fuel pressure should rise to ~40PSI. Your listed 33+ PSI under load is too low.

 

I may have mis quoted what I have for pressure. At idle it’s 30ish, rev the motor, pressure increases to 40ish psi. I don’t have the means to test while driving.

 

Is your alternator charging? What is the voltage while running? Low voltage can cause all kinds of problems.