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

Solution

1. Preparation

• Gather tools and parts.
• Safety goggles and gloves should be worn.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, ratchet, torque wrench, penetrating oil.
• Sub-steps:
  1. Locate the upstream (pre-catalytic) oxygen sensor and the downstream (post-catalytic) oxygen sensor.
  2. Apply penetrating oil to the threads of the oxygen sensors if they are corroded.
  3. Disconnect the electrical connectors from both oxygen sensors.
  4. Use the O2 sensor socket to remove the upstream sensor first, then the downstream sensor.
  5. Install new oxygen sensors by reversing the removal process, ensuring to torque them to manufacturer specifications (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter, new gaskets.
• Sub-steps:
  1. Raise the vehicle using the jack and secure it on jack stands.
  2. Locate the catalytic converter along the exhaust system.
  3. Remove any heat shields or brackets that may obstruct access to the catalytic converter.
  4. Use the exhaust pipe cutter to remove the old catalytic converter from the exhaust system.
  5. Install the new catalytic converter using new gaskets and secure it with the proper bolts.
  6. Reinstall any heat shields or brackets removed earlier.

4. Reconnect Battery and Clear Codes

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