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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on electrical systems.

2. Inspect and Clean Components

• Tools Required: Socket set, torque wrench, penetrating oil.
• Remove the oxygen sensors upstream and downstream of the catalytic converter.
• Clean the sensor threads and connectors with electric cleaner.
• Check for any debris in the exhaust ports and clean as necessary.

3. Replace Oxygen Sensors (if faulty)

• If the oxygen sensors are faulty based on diagnostic tests, replace them:
  • Sub-steps:
    • Use a socket wrench to remove the old oxygen sensors.
    • Apply anti-seize compound on the threads of the new sensors.
    • Install the new sensors and torque them to manufacturer specifications (typically around 30 ft-lbs).

4. Replace Catalytic Converter (if necessary)

• If the catalytic converter is confirmed to be inefficient:
  • Tools Required: Wrench set, cutting tool (if necessary), gasket scraper.
  • Remove the old catalytic converter by unbolting it from the exhaust system.
  • Clean the mounting surfaces on the exhaust manifold and pipe.
  • Install the new catalytic converter with new gaskets, ensuring all bolts are tightened to specification (usually around 40-50 ft-lbs).

5. Reconnect Battery and Test

• Reconnect the battery.
• Start the engine and allow it to reach operating temperature.
• Clear the P0420 code with the OBD-II scanner and perform a test drive to monitor for any recurrence of the code.