how to fix the P0420 code in my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Unplug the electrical connectors from both sensors.
3. Use an O2 sensor socket to remove the old sensors. Install new sensors by threading them in and tightening to the manufacturer's specifications (typically 30 ft-lbs).
4. Reconnect the electrical connectors securely.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. If the oxygen sensors are functioning properly, remove the heat shield if applicable.
2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe using a socket set.
3. Carefully remove the old catalytic converter and replace it with a new one, ensuring proper alignment.
4. Torque the bolts to the specified value (usually around 25-30 ft-lbs).
5. Reinstall the heat shield and ensure all connections are secure.

4. Clear Codes and Test Drive

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code.
3. Start the engine and allow it to reach operating temperature.
4. Take the vehicle for a test drive to monitor performance and ensure no codes reappear.