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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues during repair.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream O2 sensors.
  2. Disconnect the electrical connectors from both O2 sensors.
  3. Use the O2 sensor socket to unscrew the sensors from the exhaust system.
  4. Install new O2 sensors, tightening them to the manufacturer's specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust clamp tool, safety gloves.
• Sub-steps:
  1. Locate the catalytic converter and inspect for physical damage or clogging.
  2. If replacement is necessary, remove the exhaust clamps or bolts securing the catalytic converter.
  3. Carefully lower the catalytic converter from the exhaust system.
  4. Install the new catalytic converter, ensuring a secure fit and proper alignment.
  5. Reattach the exhaust clamps or bolts and tighten to the specified torque (refer to service manual for exact values).

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the engine control unit (ECU).
  3. Start the engine and allow it to reach operating temperature.
  4. Conduct a test drive to ensure the code does not reappear and observe for any unusual symptoms.