P0440 OBD II Trouble Code Evaporative Emission Control System Malfunction

Symptoms of P0440 OBD II Trouble Code

  • The gas cap is not installed or working properly
  • The purge solenoid has failed
  • The canister is plugged and not working properly

Common Causes of P0440 OBD II Trouble Code

  • Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back.
  • Inspect the EVAP system for cuts/holes in tubes/hoses
  • Inspect for damaged or disconnected hoses around the Evap purge solenoid
  • Check and/or replace the sensor
  • Check and/or replace the purge valve
  • Have a professional use a smoke machine to detect leaks