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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace the Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Sub-steps:
  1. Remove the upstream (pre-catalytic converter) oxygen sensor using the O2 sensor socket.
  2. Install the new oxygen sensor and torque it to the manufacturer’s specifications (typically around 33 lb-ft).
  3. Repeat the process for the downstream (post-catalytic converter) oxygen sensor if faulty.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter, gasket scraper.
• Sub-steps:
  1. Remove any heat shields or protective covers over the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter using a socket set.
  3. Remove the catalytic converter by unbolting it from the exhaust manifold and the exhaust system.
  4. Install the new catalytic converter, ensuring proper alignment with gaskets.
  5. Torque all bolts to the manufacturer’s specifications (typically between 25-35 lb-ft).
  6. Reinstall any heat shields or protective covers removed earlier.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code from the vehicle's computer.