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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, jack and jack stands, multimeter, safety goggles, gloves.
• Ensure the vehicle is parked on a flat surface and the engine is turned off.
• Disconnect the battery to prevent electrical shocks.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use the socket set to remove the oxygen sensors from their respective locations.
  3. Inspect the sensors for any visible damage or fouling.
  4. If faulty, replace with OEM or high-quality aftermarket sensors.
  5. Apply anti-seize compound on the threads before installing the new sensors.
  6. Torque the sensors to the manufacturer’s specifications (typically around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove the exhaust pipe that connects to the catalytic converter using the socket set.
  2. Inspect the catalytic converter for any signs of damage or clogging.
  3. If necessary, replace the catalytic converter with a new OEM part.
  4. Ensure proper alignment when installing the new catalytic converter.
  5. Reattach the exhaust pipe and torque the bolts to manufacturer specifications.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the vehicle and allow it to reach operating temperature.
  4. Take the vehicle for a test drive under various driving conditions to ensure the code does not return.