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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Using a socket wrench, carefully unscrew the sensors from their respective positions.
3. Inspect the sensor connectors for corrosion or damage; clean or replace as necessary.
4. Install the new oxygen sensors, ensuring they are torqued to the manufacturer's specifications (usually around 30 ft-lbs).
5. Reconnect the electrical connectors to the sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. If the catalytic converter is found to be damaged or blocked during inspection, proceed with replacement.
2. Disconnect the exhaust pipes from the catalytic converter using a socket set.
3. Unbolt the catalytic converter from its mounting brackets.
4. Install the new catalytic converter, ensuring proper alignment and sealing.
5. Reconnect the exhaust pipes and secure all bolts to the recommended torque specifications.

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 memory.
3. Start the engine and allow it to reach operating temperature.
4. Take the vehicle for a test drive to ensure the issue has been resolved and monitor for any reoccurrence of the check engine light.