how to fix a P0455 code in my Volkswagen Passat B8 (2015-2022)

Solution

1. Preparation

• Gather tools and parts needed.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Gas Cap

• Remove the gas cap and inspect for cracks or damage.
• If damaged, replace the gas cap with a new OEM part.
• Ensure the new gas cap is tightened properly.

3. Repair or Replace EVAP Hoses

• Locate the EVAP hoses connected to the fuel tank and vapor canister.
• Inspect for any visible cracks or signs of wear.
• If damaged, use a socket set to remove the affected hoses and replace them with new ones.
• Ensure all connections are secure.

4. Smoke Test

• Use a smoke machine to introduce smoke into the EVAP system.
• Observe for any smoke escaping from the system, indicating a leak.
• If a leak is found, repair or replace the affected component (such as the purge valve or vent valve).

5. Check and Replace Purge and Vent Valves

• Locate the purge valve and vent valve in the engine compartment and underbody respectively.
• Disconnect the electrical connectors and hoses from both valves.
• Use a multimeter to test the valves for proper operation; replace if faulty.
• Reinstall new valves if necessary, ensuring secure connections.

6. Clear Codes and Test

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0455 code.
• Start the engine and allow it to reach operating temperature.
• Conduct a test drive to ensure the check engine light does not reappear.