how to fix P0420 code on Honda Pilot YF4 (2023-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the battery to prevent electrical issues during repair.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, torque wrench, penetrating oil.
• Sub-steps:
  • Locate the upstream and downstream oxygen sensors.
  • Use penetrating oil to loosen the sensors if they are rusted.
  • Disconnect the sensor electrical connectors.
  • Remove the sensors using the O2 sensor socket.
  • Install new sensors, tightening them to manufacturer specifications (typically around 30 lb-ft).
  • Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, gasket scraper, exhaust sealant.
• Sub-steps:
  • Locate the catalytic converter along the exhaust system.
  • Remove any heat shields or brackets securing the catalytic converter.
  • Unbolt the catalytic converter from the exhaust pipes.
  • Inspect the old catalytic converter for damage or blockage.
  • Clean the mating surfaces of the exhaust pipes with a gasket scraper.
  • Install the new catalytic converter, ensuring to use new gaskets as needed and torque bolts to specifications (typically around 25 lb-ft).
  • Reinstall any heat shields or brackets removed earlier.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer system.