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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on the vehicle.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Exhaust backpressure gauge
• Multimeter

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Disconnect the electrical connectors from both sensors.
3. Use a socket wrench to remove the sensors from the exhaust system.
4. Install the new sensors, ensuring they are properly torqued to the manufacturer's specifications (typically around 30 lb-ft).
5. Reconnect the electrical connectors.

3. Replace the Catalytic Converter

1. Remove the exhaust heat shield if necessary to access the catalytic converter.
2. Use a socket set to unbolt the catalytic converter from the exhaust manifold and the exhaust pipe. Keep all the hardware for reuse.
3. Inspect the exhaust flanges for any damage; replace gaskets if worn.
4. Install the new catalytic converter and torque the bolts to the manufacturer’s specification (usually around 30 lb-ft).
5. Reinstall the exhaust heat shield if removed.

4. Clear Codes and Test

1. Reconnect the battery.
2. Use an OBD-II scanner to clear any stored codes.
3. Start the vehicle and let it reach operating temperature.
4. Take the vehicle for a test drive to ensure the check engine light does not reappear.