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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil.
• Inspect the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  • If they are damaged or malfunctioning, replace them:
    1. Apply penetrating oil to the sensor threads and allow it to soak.
    2. Disconnect the wiring harness from the oxygen sensor.
    3. Use the O2 sensor socket to remove the sensor.
    4. Install the new sensor by hand to avoid cross-threading, then torque to specifications (usually around 30 ft-lbs).
    5. Reconnect the wiring harness.

3. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, oxygen sensor socket, exhaust gasket, torque wrench.
• If the catalytic converter is found to be faulty:
  1. Raise the vehicle securely with jack stands.
  2. Disconnect the exhaust pipe from the catalytic converter by removing the bolts.
  3. Remove the oxygen sensors from the old catalytic converter (if applicable).
  4. Unbolt and remove the catalytic converter from its mounting brackets.
  5. Install the new catalytic converter with a new exhaust gasket.
  6. Reinstall oxygen sensors into the new catalytic converter, tightening to specifications.
  7. Reconnect the exhaust pipe and tighten the bolts securely.

4. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner.
• After repairs, reset the ECM:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the engine and allow it to reach operating temperature.