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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the vehicle battery to prevent any electrical issues.
• Allow the exhaust system to cool before working on it.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use a socket wrench to remove the sensors from the exhaust system.
  4. Install new oxygen sensors, ensuring they are tightened to the manufacturer's torque specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove the exhaust system components that may obstruct access to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe, taking note of the mounting positions.
  3. Inspect the gaskets and replace if necessary.
  4. Install the new catalytic converter, ensuring it is aligned correctly and fastened securely with the appropriate torque (usually around 40 lb-ft).
  5. Reattach any exhaust components removed during the process.

4. Clear Error Codes and Test

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