how to diagnose a P0455 code in my Volkswagen Golf MK7 (2015-2019)

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Gas Cap

• Check the gas cap for proper sealing.
• If damaged, replace it with a new OEM gas cap.
• Reconnect the battery terminal.

3. Repair or Replace EVAP Components

• Inspect hoses and connections; if any are cracked or disconnected, replace them.
• For the EVAP purge valve, if malfunctioning, remove the old valve:
  • Disconnect electrical connector.
  • Unbolt valve from its mounting.
  • Install the new EVAP purge valve, ensuring it is mounted securely and reconnect the electrical connector.
• If the charcoal canister is damaged, you will need to:
  • Disconnect any hoses attached to the canister.
  • Unbolt the canister from its mounting.
  • Install the new canister in reverse order of removal.

4. Conduct a Smoke Test (if needed)

• If leaks are still suspected, use a smoke machine:
  • Connect the smoke machine to the EVAP system.
  • Observe for smoke escaping, indicating a leak.
  • Repair any identified leaks.