P0091 OBD II Trouble Code Fuel Pressure Regulator 1 Control Circuit Low

Symptoms of P0091 OBD II Trouble Code

  • Delayed startup when the engine is cool
  • Black smoke from the exhaust system
  • Diminished fuel efficiency
  • Engine misfire codes and idle control codes may also accompany a P0091

Common Causes of P0091 OBD II Trouble Code

  • Shorted or open wiring and/or connectors in the fuel pressure regulator control circuit
  • Defective fuel pressure regulator
  • Faulty fuel rail pressure sensor
  • Bad PCM or a PCM programming error

Severity of P0091 OBD II Trouble Code

Since excessive fuel pressure may lead to a variety of drivability issues and cause internal engine and catalytic converter damage, a code P0091 should be considered severe.