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

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to avoid electrical issues.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the pre-catalytic and post-catalytic oxygen sensors.
  2. Use an O2 sensor socket to remove the sensors.
  3. Inspect the sensor connectors for corrosion or damage.
  4. Install new oxygen sensors, ensuring they are torqued to manufacturer specifications (typically around 30 lb-ft).
  5. Reconnect the battery terminal.

3. Inspect and Replace Catalytic Converter (if needed)

• Sub-steps:
  1. Remove any heat shields or hangers attached to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust system using a socket set.
  3. Inspect the mounting flanges for warping; replace if necessary.
  4. Install the new catalytic converter, ensuring proper alignment.
  5. Torque the bolts to manufacturer specifications (generally around 40 lb-ft).
  6. Reinstall heat shields and hangers.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the OBD-II scanner and clear the P0420 code.
  2. Start the engine and let it reach operating temperature.
  3. Take the vehicle for a test drive to ensure the check engine light does not reappear.