Neal Dameron, find a new dealer:-) P0090 - Fuel Pressure Regulator 1 Control Circuit, it controls the vacuum to the fuel pressure regulator. POSSIBLE CAUSE
PRC solenoid valve malfunction
Connector or terminal malfunction
Short to ground in wiring between PRC solenoid valve terminal B and PCM terminal 95
Open circuit in wiring between main relay terminal D and PRC solenoid valve terminal A
Open circuit in wiring between PRC solenoid valve terminal B and PCM terminal 95
Short to power circuit between PRC solenoid valve terminal B and PCM terminal 95
PCM malfunction