how to resolve P0420 code in my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface with the engine off.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use an oxygen sensor socket to remove the sensors from the exhaust system.
  4. Install new oxygen sensors in the reverse order of removal. Torque to manufacturer specifications (usually around 30-40 ft-lbs).
  5. Reconnect the electrical connectors securely.

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

• Sub-steps:
  1. Inspect the catalytic converter for physical damage or blockage.
  2. If replacement is needed, use a socket set to remove the bolts connecting the catalytic converter to the exhaust system.
  3. Carefully remove the old catalytic converter and install the new one, ensuring proper alignment.
  4. Torque the bolts to the specified value (typically around 30-45 ft-lbs).
  5. Reconnect any exhaust hangers or supports that were removed.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to ensure the check engine light does not reappear.