how to fix P0420 code on my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative battery terminal to prevent electrical issues.
• Allow the vehicle to cool down before working on the exhaust system.

2. Replace Faulty Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Disconnect the electrical connectors from both sensors.
3. Use an oxygen sensor socket to remove the sensors from the exhaust pipe.
4. Install the new sensors, making sure to apply anti-seize compound to the threads.
5. Torque the sensors to the manufacturer's specifications (usually around 30-40 ft-lbs).
6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. If the catalytic converter is damaged or efficiency is still low, remove it for inspection.
2. Use a socket set to loosen the bolts securing the catalytic converter to the exhaust manifold and pipe.
3. Remove any heat shields if present, then take out the catalytic converter.
4. Install the new catalytic converter, ensuring proper alignment with exhaust pipes.
5. Torque the bolts to the manufacturer's specifications, typically around 30 ft-lbs.
6. Reattach any heat shields that were removed.

4. Clear Error Codes

1. Reconnect the negative battery terminal.
2. Start the vehicle and allow it to reach operating temperature.
3. Use the OBD-II scanner to clear any stored error codes.
4. Perform a test drive to ensure the check engine light does not reappear.