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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical issues.

2. Replace Faulty Oxygen Sensors (if needed)

• 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 connector from the sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust pipe.
  4. Install the new sensors, ensuring they are threaded in correctly.
  5. Torque the sensors to manufacturer specifications (typically around 30 ft-lbs).
  6. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter (if faulty)

• Tools Required: Socket set, torch (if rusted), exhaust hanger removal tool
• Sub-steps:
  1. Lift the vehicle using a jack and secure it with jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Remove the exhaust bolts securing the catalytic converter using a socket set.
  4. If rusted, apply penetrating oil and use a torch to heat the bolts if necessary.
  5. Remove the exhaust hangers using the exhaust hanger removal tool.
  6. Replace with a new catalytic converter, ensuring proper alignment.
  7. Reinstall the bolts and tighten to manufacturer specifications.