how to fix P0420 code on my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Apply penetrating oil to the sensor threads and allow it to soak for a few minutes.
  3. Disconnect the electrical connectors from both sensors.
  4. Use the O2 sensor socket to unscrew and remove each sensor.
  5. Install the new sensors, tightening them to the manufacturer's specified torque (usually around 30 ft-lbs).
  6. Reconnect the electrical connectors.

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

• Tools Required: Socket set, jack stands, exhaust pipe cutter or saw, gasket scraper, new gaskets.
• Sub-steps:
  1. Raise the vehicle using jack stands for access to the underside.
  2. Inspect the catalytic converter for any visible damage or clogging.
  3. If replacement is necessary, cut the exhaust pipes using the exhaust pipe cutter.
  4. Remove the old catalytic converter by unscrewing the bolts securing it to the exhaust system.
  5. Clean the mating surfaces of the exhaust pipes with a gasket scraper.
  6. Install the new catalytic converter, ensuring the correct orientation.
  7. Secure it with bolts and new gaskets, tightening to the specified torque (typically 20-25 ft-lbs for exhaust bolts).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code and any other related codes.