how to fix P0420 code in my Toyota Camry Seventh Generation (2012-2017)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the exhaust system to cool before beginning work.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Find the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Disconnect the Sensors: Unplug the electrical connectors carefully.
3. Remove the Sensors:
   • Use an oxygen sensor socket to unscrew and remove the sensors from the exhaust manifold and catalytic converter.
4. Install New Sensors:
   • Apply anti-seize compound on the threads of the new oxygen sensors.
   • Screw the new sensors into place and torque to manufacturer specifications (usually around 30 lb-ft).
5. Reconnect the Sensors: Plug in the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove Exhaust Components:
   • Unbolt the exhaust pipe from the catalytic converter using a socket set.
   • Remove any heat shields if applicable.
2. Remove the Catalytic Converter:
   • Unbolt the catalytic converter from the exhaust manifold and remove it.
3. Install the New Catalytic Converter:
   • Position the new catalytic converter and secure it to the exhaust manifold and exhaust pipe.
   • Torque the bolts to manufacturer specifications (usually around 40 lb-ft).
4. Reinstall Heat Shields: If removed, reinstall any heat shields over the catalytic converter.

4. Final Checks

1. Reconnect the Battery: Reconnect the negative battery terminal.
2. Clear the Codes: Use the OBD-II scanner to clear any stored trouble codes.
3. Test Drive the Vehicle: Drive the vehicle under various conditions to ensure the check engine light does not reappear.