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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench

• Remove the upstream (pre-catalytic converter) oxygen sensor:

  1. Locate the O2 sensor in the exhaust manifold or pipe.
  2. Use the O2 sensor socket to unscrew and remove the sensor.
  3. Check the wiring and connector for damage; replace if necessary.
  4. Install the new O2 sensor and torque to manufacturer specifications (typically 30-40 lb-ft).

• Repeat the process for the downstream (post-catalytic converter) O2 sensor if it shows signs of malfunction.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust pipe cutter or saw, flange gasket, torque wrench
• If the catalytic converter is found to be damaged or clogged:
  1. Raise the vehicle securely on jack stands.
  2. Undo the flange bolts connecting the catalytic converter to the exhaust pipe.
  3. Cut the exhaust pipes if necessary to remove the old catalytic converter.
  4. Install the new catalytic converter using new gaskets and torque the bolts to specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the stored P0420 code.

5. Final Checks

• Start the vehicle and allow it to reach operating temperature.
• Monitor the exhaust system for leaks and ensure all connections are secure.