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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the exhaust system to cool completely before working.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, wrench set, penetrating oil.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust manifold and catalytic converter.
  2. Apply penetrating oil to the sensor threads and wait a few minutes.
  3. Use the O2 sensor socket to remove the sensors.
  4. Install new oxygen sensors by reversing the removal process and torque to manufacturer specifications (usually around 30 lb-ft).

3. Check and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter, gasket scraper.
• Sub-steps:
  1. Remove the exhaust pipe bolts connecting the catalytic converter to the exhaust system.
  2. Cut the exhaust pipe if necessary to remove the old catalytic converter.
  3. Clean the gasket surfaces on both the exhaust pipe and the exhaust manifold.
  4. Position the new catalytic converter and secure it with bolts, ensuring proper alignment.
  5. Torque bolts to manufacturer specifications (typically around 40 lb-ft).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.