Are you getting an error code that is telling you this? P0193......
Possible issues for a fuel rail pressure sensor circuit high input error;
- Low or no fuel
- Fuel Rail Pressure Sensor harness is open or shorted
- Fuel Rail Pressure Sensor circuit poor electrical connection
- Faulty Fuel Rail Pressure Sensor
- Faulty Fuel Pump
Have you tested anything or are you just going off an assumption that it is the sensor that is at fault? could be a loose wire or low fuel pressure! Cheaper to test these things than to just throw parts at them. 
A lot of mechanics/shops will scan your car and tell you to replace a part based on the code. Often, it's not the part that's faulty, and you will keep replacing things until you discover that it was a loose wiring connection (or some other simple fix) all along.
GhostTribute has it right--there are a number of conditions that can cause that code, so it's better to spend a bit more on diagnosis than to start replacing parts and hope you get lucky on the first try.
Sailor mentioned to pull that vacuum hose and check if there's fuel in the hose, and if so, then you need that sensor. Also check that the wiring connector is tight, and for broken insulation or corrosion/moisture. That will eliminate two of the potential causes...or confirm one.