Thanks Nero, made some compared readings against a hyster with the same motor and got different measurements using an old pressure gage. The truck that runs good had 10psi idle - 15psi WOT. The problem truck runs 15psi idle and 25psi WOT@ 1900 RPM, Let throttle off and pressure went to 30psi motor stalls and pressure slowly climbed to 40psi. Starting to think it's a regulator problem. I know my gage will not be accurate, but the readings are too different to ignore and how do I adjust the pressure? Thanks Nero and have a good weekend.

Set gas pressure to 5 psi

Nero

Nero, thanks for the info. Will look into it. I checked the fuel rail pressure, about 10psi. Is that the normal pressure? And what else could make this vortec 2400 loose so much power? Again thanks.

Hi Harley,
All I can tell you about that code is that it is referring to the oil pressure sensor so that needs checking out also it's associated wiring.
The oil pressure sensor is reading low which may mean the sensor has shorted out or the wiring has. I would have thought the engine would have shut down within 30 seconds if that was the case still it needs checking out.

Regards Nero