how to fix P0420 code on Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the battery to prevent any electrical issues during the repair.

2. Inspect and Replace Oxygen Sensors

1. Tools Required: O2 sensor socket, wrench set, and multimeter.
2. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
3. Disconnect the electrical connectors from both sensors.
4. Remove the sensors using the O2 sensor socket and inspect for wear or carbon buildup.
5. If necessary, replace the sensors with new, compatible units.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Tools Required: Socket set, torque wrench, and exhaust hanger removal tool.
2. Remove the exhaust pipe from the catalytic converter by loosening the clamps and bolts.
3. If needed, remove the mounting brackets using the socket set.
4. Carefully remove the catalytic converter from its position.
5. Install the new catalytic converter by reversing the removal steps, ensuring all bolts are torqued to the manufacturer's specifications (typically around 30-40 lb-ft).
6. Reattach the exhaust pipe and clamps securely.

4. Reconnect Battery and Clear Codes

1. Reconnect the battery terminals, ensuring the connections are tight.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.