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

Solution

1. Preparation

• Gather the necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Unplug the electrical connectors from the oxygen sensors.
  3. Using the O2 sensor socket, carefully remove the sensors from the exhaust system.
  4. Install new oxygen sensors, ensuring they are properly torqued to manufacturer specifications (usually around 30-40 ft-lbs).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary)
• Sub-steps:
  1. Inspect the catalytic converter for signs of damage or blockage.
  2. If replacement is necessary, unbolt the catalytic converter from the exhaust system.
  3. If the converter is welded, use an exhaust pipe cutter to remove it carefully.
  4. Install the new catalytic converter, ensuring all gaskets are in place.
  5. Torque the bolts to manufacturer specifications.

4. Clear Codes and Test

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the system.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to ensure the check engine light does not reappear.