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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical short circuits.
• Allow the exhaust system to cool before working.

2. Inspect and Replace Oxygen Sensors

1. Remove the negative battery cable to ensure safety.
2. Locate the oxygen sensors (upstream before the catalytic converter and downstream after it).
3. Unplug the electrical connectors from both sensors.
4. Use an O2 sensor socket to remove the old sensors.
5. Install new oxygen sensors by threading them into the exhaust pipe and tightening them to the manufacturer's specification (usually around 30 ft-lbs).
6. Reconnect the electrical connectors to the sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Visually inspect the catalytic converter for any signs of damage or excessive carbon buildup.
2. If the catalytic converter is damaged, remove the exhaust pipe that connects it to the engine using a socket set.
3. Unbolt the catalytic converter from its mounting points.
4. Install the new catalytic converter by reversing the removal steps, ensuring all bolts are torqued to manufacturer specifications.
5. Reattach the exhaust pipe and ensure all connections are sealed.

4. Clear Codes and Test Drive

1. Reconnect the negative battery cable.
2. Use the OBD-II scanner to clear the P0420 code from the ECM.
3. Start the engine and allow it to reach operating temperature.
4. Conduct a test drive to ensure the check engine light remains off.