Alright, I've got a 2003 F550 with a 7.3. Before I started here, a tech started to work on this old girl. He changed all 8 injectors, both heads, turbo, crank vent, fuel lines to head, the CPS, engine wire harness and spliced into the main harness. Currently its a no start. Oil pressure to nozzles are only 32 psi not enough to fire. the camshaft sensor is new, but nothing reading on the tach when trying to start. Everything LOOKS right. The only thing I can find wrong is the exhaust backpressure sensor is broke and they tried putting just the plug on the 2 pins. Cranks find, just no start. I'm thinking that the HPOP is inop. Any ideas?