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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to avoid electrical shorts.

2. Replace Oxygen Sensors (if faulty)

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Remove the electrical connectors from both sensors.
3. Use an oxygen sensor socket to unscrew and remove the faulty sensors.
4. Install new oxygen sensors by threading them into their respective locations; torque to manufacturer specifications (typically around 30 lb-ft).
5. Reconnect the electrical connectors for both sensors.

3. Inspect and Replace Catalytic Converter (if needed)

1. Remove the exhaust system components leading to the catalytic converter (e.g., heat shields, brackets).
2. Disconnect the catalytic converter from the exhaust manifold and downstream exhaust pipe.
3. Inspect the old catalytic converter for any signs of damage or clogging.
4. Install the new catalytic converter, ensuring proper alignment and secure all bolts to the specified torque settings.
5. Reinstall any removed exhaust components and check for proper fitment.

4. Clear Codes and Test

1. Reconnect the battery.
2. Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.
3. Start the engine and allow it to reach operating temperature.
4. Take the vehicle for a test drive to monitor performance and check for the reappearance of the check engine light.