how to fix P0420 code on my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery.
• Allow the engine to cool before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, anti-seize compound.
• Remove the upstream (pre-catalytic) oxygen sensor:
  • Disconnect the electrical connector.
  • Use the O2 sensor socket to unscrew the sensor.
  • Apply anti-seize compound to the threads of the new sensor.
  • Install the new sensor and torque it to the manufacturer’s specifications (usually around 30-35 ft-lbs).
• Repeat for the downstream (post-catalytic) oxygen sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, exhaust pipe cutter, gasket maker.
• Raise the vehicle safely using jack stands.
• Remove the exhaust pipes connected to the catalytic converter:
  • Use the socket set to unbolt the connections.
  • If the exhaust is rusted or damaged, use an exhaust pipe cutter.
• Remove the old catalytic converter.
• Install the new catalytic converter, ensuring proper alignment.
• Reconnect the exhaust pipes and use gasket maker on the connections if necessary.
• Torque all connections as specified by the manufacturer.