Fuel Rail Pressure Sensor ?????
Fuel pressure is regulated at the pump. Do you have a code?
If you think you're having a fuel delivery problem, get hold of a fuel pressure gage. Preferably one with a 4 - 5 foot hose. If you don't see a problem parked, duck tape it to the windshield and drive around. A common problem with new fuel pump installations is neglecting to clean the crud from the bottom of the tank.
If the fuel pressure responds normally, move on to other causes.
Since you have an aftermarket intake, keep the MAF clean from any filter oil.
Make sure your IMRC is working correctly.
Make sure the plug wires are not misfiring (view at night).
Vacuum leaks (the PCV hose is common), the TPS, and other parts of the ignition system are also suspect.
