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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety during the repair process.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use the O2 sensor socket to remove both sensors from the exhaust manifold and catalytic converter.
  4. Install the new oxygen sensors and torque them to the manufacturer’s specifications (usually around 30 lb-ft).
  5. Reconnect the electrical connectors to the oxygen sensors.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if necessary), torque wrench
• Sub-steps:
  1. Safely lift the vehicle using jack and jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Inspect for any signs of physical damage or blockage.
  4. If replacement is necessary, use an exhaust pipe cutter to remove the old catalytic converter.
  5. Install the new catalytic converter, ensuring all gaskets and seals are in place.
  6. Torque the bolts to the specified manufacturer’s settings.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use an 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 that the check engine light does not reappear.