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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Allow the engine to cool before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench, penetrating oil.
• Inspect the upstream and downstream oxygen sensors for proper operation.
• If faulty, remove the old oxygen sensor:
  • Apply penetrating oil to the threads if they are rusted.
  • Use an O2 sensor socket to unscrew the sensor.
• Install the new sensor:
  • Apply anti-seize compound to the threads (if required).
  • Torque to manufacturer specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary).
• Inspect the catalytic converter for blockages or damage.
• If replacement is necessary:
  • Remove the exhaust pipes connected to the catalytic converter.
  • Use a socket set to unbolt the converter from the exhaust manifold and the mid-pipe.
  • Install the new catalytic converter:
    • Ensure proper alignment with the exhaust system.
    • Torque bolts to manufacturer specifications (usually around 30-40 lb-ft).

4. Clear Error Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.