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

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is on a level surface and secure it with jack stands if elevated.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Disconnect the connectors: Carefully unplug the electrical connectors from both sensors.
3. Remove the sensors: Use an oxygen sensor socket to remove the sensors from their mounting locations.
4. Install new sensors: Apply anti-seize compound to the threads of the new sensors. Install and torque them to the manufacturer’s specifications (usually around 30 ft-lbs).
5. Reconnect the connectors: Plug the electrical connectors back into the new sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Check the catalytic converter: If the previous steps do not resolve the issue, inspect the catalytic converter for physical damage or clogging.
2. Remove the old catalytic converter: Disconnect the exhaust pipe and any mounting brackets. Use a socket set to remove bolts securing the catalytic converter.
3. Install the new catalytic converter: Position the new catalytic converter into place. Secure it with the original bolts or new ones as required, torquing to manufacturer specifications (typically around 30 ft-lbs).
4. Reattach exhaust components: Reconnect the exhaust system, ensuring all joints are sealed properly.

4. Reset the ECU

1. Reconnect the battery: Ensure all connections are secure.
2. Use the OBD-II scanner: Clear the P0420 code and any other stored trouble codes from the ECU.