how to fix P0420 code in Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to avoid electrical shorts.
• Allow the exhaust system to cool completely before starting work.

2. Inspect and Replace Oxygen Sensors (if necessary)

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Use an O2 sensor socket to remove the sensors.
3. Inspect the sensors for damage or excessive carbon buildup.
4. If faulty, install new oxygen sensors using anti-seize compound on the threads.
5. Torque the sensors to the manufacturer’s specifications (typically around 30 ft-lbs).

3. Replace Catalytic Converter (if necessary)

1. Remove the exhaust heat shield if applicable.
2. Unbolt the catalytic converter from the exhaust system using a socket set and wrench.
3. Inspect the mounting points and gaskets; replace them if damaged.
4. Install a new catalytic converter, ensuring proper alignment with the exhaust pipes.
5. Torque the bolts to the manufacturer’s specifications (usually around 40-50 ft-lbs).
6. Reinstall any heat shields removed earlier.

4. Clear Codes and Test

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code from the computer.
3. Start the engine and allow it to reach operating temperature.
4. Take the vehicle for a test drive to verify that the check engine light does not return.