DTC P0087: Fuel Rail Pressure - Low: Description
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The Engine Control Module (ECM) monitors Fuel Rail Pressure (FRP) using the FRP sensor. If the sensor indicates a pressure less than the commanded rail pressure plus a possible transitional overshoot, the ECM will set Diagnostic Trouble Code (DTC) P0087 for fuel rail pressure too low.