P018F OBD II Trouble Code Fuel System Over Pressure Relief Valve Frequent Activation

How to quickly diagnose, repair, and info on symptoms and causes of a P018F code that indicates a fuel relief valve activation problem.

Symptoms of P018F OBD II Trouble Code

  • Rich exhaust conditions
  • Rough idle; especially upon cold start
  • Diminished fuel efficiency
  • Engine misfire codes due to fouled spark plugs

Common Causes of P018F OBD II Trouble Code

  • Bad fuel pressure sensor
  • Defective fuel pressure regulator
  • Insufficient vacuum to the fuel pressure regulator
  • Open or shorted fuel pressure sensor or electronic fuel pressure regulator circuits
  • Faulty PCM or a PCM programming error

Severity of P018F OBD II Trouble Code

Because excessive fuel pressure is a contributing factor in a code P018F being stored, and because excessive fuel pressure may result in serious mechanical damage, this code must be considered severe.