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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine and exhaust components to cool down.

2. Inspect and Replace Oxygen Sensors

• Remove the upstream (pre-catalytic converter) oxygen sensor:
  • Use an O2 sensor socket and wrench to carefully unscrew the sensor.
• Install the new upstream oxygen sensor:
  • Apply anti-seize compound to the threads (if required).
  • Torque the sensor to the manufacturer’s specifications (usually around 30-40 lb-ft).
• Repeat for the downstream (post-catalytic converter) oxygen sensor if needed.

3. Inspect and Replace the Catalytic Converter

• Remove the catalytic converter:
  • Use a socket set to unbolt the converter from the exhaust pipe.
  • Be cautious of exhaust hangers; you may need to remove them to free the converter.
• Install the new catalytic converter:
  • Align it properly and secure it with bolts, torquing them to specifications (usually around 30-40 lb-ft).
• Reconnect any exhaust hangers removed during the process.

4. Clear Codes and Test Drive

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature; monitor for any codes.