why does my Ford F-150 13th Generation (2015-2020) have a check engine light with P0456 code

Learn how to diagnose and fix P0456 code indicating a small EVAP leak in Ford F-150 (2015-2020). Step-by-step guide with tools and procedures.

Solution

1. Preparation

• Tools Required: OBD-II scanner, basic hand tools, smoke machine, vacuum gauge.
• Ensure the vehicle is parked on a level surface and the engine is turned off.
• Disconnect the battery to prevent electrical shorts while working on the system.

2. Inspect and Replace Fuel Filler Cap

• Remove the fuel filler cap and inspect for any signs of wear or damage:
  • If damaged, replace with a new OEM fuel filler cap.
  • Reinstall the new cap securely and ensure it clicks into place.

3. Inspect EVAP Hoses and Lines

• Trace all EVAP hoses from the fuel tank to the EVAP canister:
  • Check for cracks, loose connections, or blockages.
  • Replace any damaged hoses with OEM parts.
  • Ensure all connections are tight and secure.

4. Test with Smoke Machine

• Connect the smoke machine to the EVAP system:
  • Introduce smoke into the system and observe for any escaping smoke.
  • Locate and repair any leaks found.

5. Check Purge and Vent Valves

• Remove and inspect the purge valve and vent valve:
  • Ensure they are functioning properly and are not stuck open or closed.
  • If either valve is faulty, replace with an OEM part.

6. Reconnect Battery and Clear Codes

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the P0456 code.
• Start the engine and allow it to run to check for the return of the check engine light.