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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts.
• Ensure the vehicle is safely elevated on jack stands if accessing the exhaust system underneath.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: The upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors are typically located near the catalytic converter.
2. Disconnect the electrical connectors: Carefully unclip and remove the connectors from the oxygen sensors.
3. Remove the sensors: Use an oxygen sensor socket to unscrew the sensors from the exhaust system.
4. Install new sensors:
   • Apply anti-seize compound on the threads of the new sensors.
   • Screw in the new sensors and tighten to manufacturer specifications (usually around 30 ft-lbs).
5. Reconnect the electrical connectors.

3. Replace Catalytic Converter (if necessary)

1. Remove the exhaust components: Depending on the vehicle design, remove bolts and hangers that secure the exhaust before the catalytic converter.
2. Disconnect the catalytic converter: Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
3. Install the new catalytic converter:
   • Position the new catalytic converter and secure it with bolts.
   • Ensure proper alignment with the exhaust system.
4. Reinstall all exhaust components: Tighten bolts to the manufacturer’s torque specifications.

4. Final Checks

1. Reconnect the battery: Reattach the negative terminal.
2. Clear the error codes: Use the OBD-II scanner to clear the P0420 code.
3. Start the engine: Allow it to reach operating temperature and monitor for any check engine light reoccurrence.