There is a sensor on the fuel rail that monitors fuel pressure at the rail to determine fuel pressure and vary the pump speed accordingly. The PCM (powertrain control module) or ECM (engine control module) has detected that fuel pressure is below specification for the supply commanded to the fuel pump driver module or fuel pump assembly.

 

Yes, we have replaced that sensor under the valve cover. I understand that rail pressure is what is causing these codes, but I'm at a loss as to why it is throwing this code still. All the supply lines look good (not smashed/bent) I've been told a leaking injector can cause this problem but it's not making any oil to lead me to believe that's the problem.

I should also mention that it doesn't throw codes all the time sometimes it will go fine without issues for a few days (couple hundred miles) then it shows back up, clear codes multiple times then eventually it will run fine again for a few more days.

 

the injectors may be leaking out the return side (back to the tank)..not necessarily into the engine oil.