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

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery for safety.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust pipes.
  4. Install the new oxygen sensors by threading them into the exhaust system and tightening them to the manufacturer’s specifications (usually around 30-40 lb-ft).
  5. Reconnect the electrical connectors to the sensors.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, cutting tool (if needed), exhaust sealant, torque wrench
• Sub-steps:
  1. Inspect the catalytic converter for any signs of damage or clogging.
  2. If replacement is needed, unbolt the catalytic converter from the exhaust system. You may need to cut the exhaust pipes if they are rusted or fused.
  3. Install the new catalytic converter, ensuring proper alignment with the exhaust system.
  4. Torque the bolts to the manufacturer's specifications (typically around 30-40 lb-ft) and use exhaust sealant on connections if necessary.
  5. Ensure all connections are secure and leak-free.