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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Ensure the vehicle is on a level surface and securely supported using jack stands.

2. Inspect and Replace Oxygen Sensors

• Remove the upstream oxygen sensor using an oxygen sensor socket.
• Install the new upstream oxygen sensor and torque to manufacturer specifications (typically around 30 ft-lbs).
• Repeat the process for the downstream oxygen sensor if it shows signs of failure or if replacing the catalytic converter.

3. Inspect and Replace Catalytic Converter (if necessary)

• If the oxygen sensors are functioning correctly, proceed to inspect the catalytic converter.
• Remove the exhaust pipe bolts connecting to the catalytic converter using a socket set.
• Carefully detach the catalytic converter from the exhaust system.
• Install the new catalytic converter, ensuring proper alignment and sealing of the exhaust joints.
• Torque all bolts to the manufacturer’s specifications.

4. Reconnect Battery and Reset Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.

5. Test Drive

• Perform a test drive to ensure the code does not return and the vehicle operates normally.