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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, jack and jack stands, safety glasses, gloves.
• Allow the engine to cool completely before beginning work.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the pre-catalytic and post-catalytic oxygen sensors.
  2. Disconnect the electrical connectors from the sensors.
  3. Using a socket wrench, remove the sensors from their respective locations.
  4. Install new oxygen sensors by threading them into place and tightening to the manufacturer's torque specifications (typically around 30-35 lb-ft).
  5. Reconnect the electrical connectors for both sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Elevate the vehicle using a jack and secure it with jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Disconnect the exhaust pipes leading to and from the catalytic converter using a socket set.
  4. Remove any supporting brackets or bolts that secure the catalytic converter.
  5. Replace the old catalytic converter with the new unit, ensuring proper alignment.
  6. Reinstall the exhaust pipes and secure them with bolts, tightening them to the manufacturer's specifications.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the memory.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive under various conditions to verify that the check engine light does not reappear.