how to fix P0420 code on my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is on a flat surface and safely supported.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust pipe.
2. Use an O2 sensor socket to remove the upstream oxygen sensor (before the catalytic converter).
3. Install the new upstream oxygen sensor and torque it to the manufacturer's specification (typically around 30 lb-ft).
4. Repeat the process for the downstream oxygen sensor (after the catalytic converter) if it's also faulty.

3. Inspect and Replace the Catalytic Converter

1. If the catalytic converter is damaged or the efficiency test fails, remove the exhaust components connected to the catalytic converter.
2. Remove the bolts securing the catalytic converter using a socket set.
3. Carefully remove the catalytic converter from the exhaust system.
4. Install the new catalytic converter, ensuring it’s aligned correctly with the exhaust pipes.
5. Torque all bolts to the manufacturer's specifications (usually around 30 lb-ft for exhaust connections).
6. Reconnect any exhaust hangers that were removed during the process.

4. Clear Codes and Test Drive

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
3. Perform a test drive to ensure the vehicle operates normally and monitor for the check engine light.