how to fix P0456 code for EVAP leak in my Toyota Highlander XU70 (2020-Present)?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the negative battery terminal to avoid electrical shock.

2. Inspect and Replace the Gas Cap

• Tools Required: None
• Inspect the gas cap for damage; if defective, replace with a new OEM gas cap.
• Tighten the gas cap until it clicks securely.

3. Inspect and Replace EVAP Hoses

• Tools Required: Socket set, pliers
• Remove any fasteners securing the EVAP hoses.
• Inspect hoses for cracks or damage; replace any damaged hoses with OEM parts.
• Reattach hoses and ensure connections are tight.

4. Replace Purge Valve and Vent Valve (if necessary)

• Tools Required: Socket set, pliers
• Disconnect the electrical connectors from the purge and vent valves.
• Remove the mounting bolts and take out the faulty valves.
• Install new OEM purge and vent valves, ensuring all connections are secure.

5. Perform a Smoke Test

• Tools Required: Smoke machine
• Connect the smoke machine to the EVAP system.
• Activate the smoke machine to introduce smoke into the system.
• Observe for smoke escaping from any leaks; repair as necessary.

6. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear all codes from the system.
• Test drive the vehicle for at least 20 minutes to ensure the check engine light does not reappear.