how to fix P0420 code on Honda Pilot YF3 (2016-2022)?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent any electrical issues.
• Raise the vehicle using a hydraulic lift or jack stands and secure it properly.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil.
• Use the O2 sensor socket to carefully remove the upstream (pre-catalytic converter) oxygen sensor.
  • Check for any signs of damage or contamination.
  • Install the new sensor by threading it in by hand and then tightening with the torque wrench to manufacturer specifications (typically around 30 lb-ft).
• Repeat this process for the downstream (post-catalytic converter) O2 sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust gasket.
• Remove the bolts securing the catalytic converter to the exhaust system using the socket set.
• Carefully lower the catalytic converter and inspect it for any signs of damage or clogging.
• Install the new catalytic converter, ensuring that new gaskets are used and that bolts are tightened to the specified torque (typically around 30-40 lb-ft).

4. Clear Codes and Test

• Reconnect the battery and use an OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Monitor the O2 sensor readings and ensure they cycle correctly.