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.
• Allow the exhaust system to cool before working.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the pre-catalytic and post-catalytic oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use an oxygen sensor socket to remove the sensors from the exhaust system.
  4. Install new oxygen sensors in the same position, ensuring they are tightened to the manufacturer's specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors to the sensors.

3. Check and Repair Exhaust Leaks

• Sub-steps:
  1. Inspect all exhaust joints, including gaskets and connections, for leaks.
  2. If leaks are found, replace damaged gaskets or tighten loose connections.
  3. If significant damage is present in the exhaust pipe, cut out the damaged section and weld in a new piece or replace the entire component.

4. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the bolts securing the catalytic converter to the exhaust system using a socket set.
  2. Inspect the converter for signs of clogging or physical damage.
  3. If the converter is defective, replace it with a new unit, ensuring proper fitment and bolting (torque to manufacturer specifications).
  4. Reinstall any heat shields that were removed during the process.

5. Clear the Codes and Test

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  3. Start the vehicle and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to verify the repair.