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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool down before working on the exhaust system.

2. Oxygen Sensor Replacement (if necessary)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Using an oxygen sensor socket, carefully unscrew the faulty sensor from the exhaust pipe.
  3. Apply anti-seize compound to the threads of the new sensor (if applicable).
  4. Install the new sensor and tighten it to the manufacturer's specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connector of the new oxygen sensor.

3. Catalytic Converter Inspection/Replacement

• Sub-steps:
  1. If the catalytic converter is damaged or clogged, support the vehicle securely on jack stands.
  2. Remove any heat shields or components obstructing access to the catalytic converter.
  3. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
  4. Inspect the mounting surfaces for any debris or damage; clean if necessary.
  5. Install the new catalytic converter and tighten bolts to manufacturer specifications (typically around 30 lb-ft).
  6. Reinstall any heat shields or components that were removed.

4. Reset the Check Engine Light

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0420 code from the vehicle's computer.