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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream O2 sensor:
   • Use an O2 sensor socket to unscrew the sensor from the exhaust manifold.
   • Disconnect the electrical connector.
2. Install new upstream O2 sensor:
   • Apply anti-seize compound to the threads of the new sensor.
   • Screw in the sensor and connect the electrical connector.
   • Torque the sensor to the manufacturer’s specifications (typically around 30-35 ft-lbs).
3. Repeat for the downstream O2 sensor if it shows signs of malfunction during testing.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove exhaust components:
   • Unbolt the exhaust pipe from the catalytic converter using a socket set.
   • Disconnect any hangers or clamps securing the converter.
2. Install new catalytic converter:
   • Position the new catalytic converter in place.
   • Reconnect all exhaust components and secure them with new gaskets if needed.
   • Torque the bolts to the manufacturer's specifications (usually around 20-25 ft-lbs).
3. Reconnect any sensors:
   • Ensure all O2 sensors are connected and secure.

4. Final Checks

1. Reconnect the battery and start the engine.
2. Clear the error codes using the OBD-II scanner.
3. Perform a test drive under various conditions (city and highway) to allow the system to monitor the catalytic converter’s performance.