P0440 Evaporative Emission Control System

Powertrain Severity: Low Generic OBD-II

General fault in the EVAP system that stores and burns fuel vapour.

Common causes

  • Loose or faulty fuel cap
  • Leaking EVAP hose
  • Faulty purge or vent valve

Symptoms

  • Check engine light
  • Fuel smell

What to check

  1. Check the fuel cap seal
  2. Smoke-test the EVAP system
  3. Test purge and vent valves

Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0440, follow the service information for that make and model.

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