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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.

2. Inspect and Replace Oxygen Sensors (if needed)

• Tools Required: O2 sensor socket, wrench set.
• If diagnostic steps indicate a faulty O2 sensor:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Carefully disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the faulty sensor(s).
  4. Install new O2 sensor(s) and torque to manufacturer specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors.

3. Check and Replace Catalytic Converter (if needed)

• Tools Required: Jack and jack stands, socket set.
• If diagnostics confirm a faulty catalytic converter:
  1. Raise the vehicle and secure it on jack stands.
  2. Disconnect the exhaust flange bolts connecting the catalytic converter to the exhaust system.
  3. Remove any brackets or hangers securing the catalytic converter.
  4. Take out the old catalytic converter and replace it with a new one, ensuring proper alignment.
  5. Reattach the exhaust flange and secure with bolts (torque to manufacturer specifications, usually around 25 ft-lbs).
  6. Reinstall any brackets or hangers removed.

4. Clear Codes and Test Drive

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0420 code.
• Test drive the vehicle for a thorough evaluation of performance.