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 negative battery terminal to avoid electrical shorts.

2. Inspect and Repair Exhaust System

• Sub-steps:

  1. Visually inspect the entire exhaust system for leaks, especially around joints and connections.
  2. If a leak is found, repair or replace the damaged section of the exhaust pipe using appropriate welding or sealant.

• Tools Required:

  • Socket set
  • Exhaust sealant or welding equipment

3. Test and Replace Oxygen Sensors (if necessary)

• Sub-steps:

  1. Using a multimeter, test the voltage output of the upstream and downstream oxygen sensors.
  2. If the sensors are out of specification, disconnect the wiring harness and remove the sensors using an oxygen sensor socket.
  3. Install new oxygen sensors, ensuring they are properly torqued (typically around 30 lb-ft).

• Tools Required:

  • Multimeter
  • Oxygen sensor socket
  • Torque wrench

4. Inspect and Replace Catalytic Converter (if required)

• Sub-steps:

  1. Remove the catalytic converter by unbolting it from the exhaust system (ensure to support the exhaust).
  2. Inspect for any blockages or damage; if damaged, replace it with a new catalytic converter specific to the Tacoma N300.
  3. Reinstall the new catalytic converter, ensuring all bolts are torqued to manufacturer specifications.

• Tools Required:

  • Socket set
  • Torque wrench