how to fix P0420 code on Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, jack and jack stands.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Raise the vehicle using a jack and secure it with jack stands.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Disconnect the electrical connectors from both sensors.
3. Use a socket wrench to remove both oxygen sensors from their respective bungs.
4. Inspect the threads and seals for damage; replace if necessary.
5. Install the new oxygen sensors, ensuring they are tightened to the manufacturer's specifications (typically around 30-40 lb-ft).
6. Reconnect the electrical connectors to both sensors.

3. Inspect and Replace Catalytic Converter

1. If oxygen sensors are functioning properly, check the catalytic converter for blockages or damage.
2. Remove the exhaust pipe that connects to the catalytic converter using a socket set.
3. Unbolt the catalytic converter from its mounting points.
4. Replace it with a new catalytic converter, ensuring proper alignment.
5. Torque all bolts to the manufacturer's specifications.
6. Reinstall the exhaust pipe and ensure all connections are tight and leak-free.

4. Reconnect Battery and Clear Codes

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
3. Start the engine and allow it to reach operating temperature.