how to fix the P0420 error code on my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Raise the vehicle using jack stands if necessary.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Use an O2 sensor socket to remove the faulty sensor(s).
  3. Apply anti-seize compound to the threads of the new oxygen sensor.
  4. Install the new sensor(s) and torque to manufacturer's specifications (typically around 30 ft-lbs).

Tools Required:

• OBD-II scanner
• Multimeter
• Infrared thermometer
• O2 sensor socket
• Torque wrench
• Anti-seize compound

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

• Sub-steps:
  1. Disconnect the exhaust pipes connected to the catalytic converter using a socket set.
  2. Remove any mounting brackets or bolts securing the catalytic converter.
  3. Carefully remove the old catalytic converter.
  4. Install the new catalytic converter in reverse order of removal, ensuring proper alignment.
  5. Reconnect the exhaust pipes and torque bolts to specifications (usually around 40-50 ft-lbs).

Tools Required:

• Socket set
• Torque wrench
• Exhaust hanger removal tool (if applicable)