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

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the vehicle battery to ensure safety.
• Allow the exhaust system to cool before starting work.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Use an O2 sensor socket to remove the upstream oxygen sensor.
3. Install the new upstream oxygen sensor and torque it to the manufacturer’s specifications (typically around 30 Nm).
4. Repeat the removal and installation process for the downstream oxygen sensor.
5. Reconnect the battery and clear any stored OBD-II codes.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the exhaust heat shield if applicable.
2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe using a socket set.
3. If the catalytic converter is damaged, replace it with a new unit that meets OEM specifications.
4. Torque the new catalytic converter bolts according to manufacturer specifications.
5. Reinstall the heat shield if removed.

4. Final Checks

1. Reconnect the vehicle battery.
2. Start the engine and allow it to reach operating temperature.
3. Monitor exhaust emissions and check for any new error codes using the OBD-II scanner.