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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool down completely.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream oxygen sensor (usually located before the catalytic converter):
  • Use the O2 sensor socket to unscrew the sensor.
  • Inspect for carbon buildup or damage.
• Replace with a new oxygen sensor if necessary (ensure it is compatible with your model).
• Install the new sensor and torque to the manufacturer's specification (usually around 30 ft-lbs).

3. Inspect and Replace the Catalytic Converter

• Tools Required: Wrench set, jack and jack stands, exhaust hangers removal tool
• Raise the vehicle and secure it on jack stands.
• Remove any heat shields covering the catalytic converter if necessary.
• Unbolt the catalytic converter from both the exhaust pipe and the exhaust manifold.
• Inspect for any signs of internal damage (such as rattling or blockage).
• Install a new catalytic converter, ensuring proper alignment.
• Torque all bolts to the manufacturer's specifications.

4. Reconnect Battery and Test

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.
• Use the OBD-II scanner to clear the P0420 code and monitor for any reoccurrence.