how to fix P0420 code on my Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent any electrical issues during the repair process.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream and downstream oxygen sensors located before and after the catalytic converter.
2. Disconnect the Sensors: Carefully unplug the electrical connectors from both oxygen sensors.
3. Remove the Sensors: Use an oxygen sensor socket to unscrew the sensors from the exhaust system.
4. Install New Sensors: Apply anti-seize compound to the threads of the new sensors and install them by hand, then tighten them to the manufacturer's specification (usually around 30-50 ft-lbs).
5. Reconnect the Sensors: Plug the electrical connectors back into the new oxygen sensors.

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

1. Inspect the Catalytic Converter: Check for any damage, clogs, or excessive heat discolouration.
2. Remove the Old Catalytic Converter:
   • Loosen the clamps or bolts securing the catalytic converter to the exhaust pipes.
   • Remove the old catalytic converter from the exhaust system.
3. Install the New Catalytic Converter:
   • Position the new catalytic converter in place and secure it with new clamps or bolts.
   • Ensure all connections are tight and properly sealed.
4. Reconnect the Battery: Reattach the battery terminals, ensuring a secure connection.