how to fix P0420 code on my Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent electrical shorts during repairs.
• Raise the vehicle securely on jack stands if access to the exhaust system is needed.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Locate the upstream and downstream oxygen sensors on the exhaust system.
• Using a socket wrench, carefully remove the oxygen sensors.
• Inspect the threads for damage; clean the sensor ports if necessary.
• Install new oxygen sensors (OEM recommended) and torque them to the manufacturer’s specifications (usually around 30 lb-ft).
• Reconnect the electrical connectors securely.

3. Check and Replace Catalytic Converter (if necessary)

• If the catalytic converter is damaged or blocked, it must be replaced.
• Using a cutting tool, carefully cut the exhaust pipes before and after the catalytic converter.
• Remove the old catalytic converter from the exhaust system.
• Install the new catalytic converter, ensuring proper alignment.
• Use exhaust pipe clamps or weld joints to secure the connections, following torque specifications.

4. Reassemble and Reconnect

• Reattach any heat shields or components removed during the process.
• Ensure all exhaust connections are tight and leak-free.
• Reconnect the battery.

5. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Start the engine and allow it to reach operating temperature.
• Take the vehicle for a test drive to ensure the check engine light does not reappear.