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

Solution

1. Preparation

• Tools Required: OBD-II scanner, jack and jack stands, socket set, multimeter, safety glasses, gloves.
• Disconnect the negative terminal of the battery to ensure safety while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the pre-catalytic and post-catalytic oxygen sensors.
  2. Using a socket set, remove the oxygen sensors carefully to avoid damage to the threads.
  3. Inspect the sensors for any signs of wear or corrosion. If they are faulty, replace them with new ones.
  4. Reinstall the new sensors, tightening them to the manufacturer’s specifications (typically around 30 Nm or 22 lb-ft).

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Support the vehicle securely on jack stands.
  2. Remove the exhaust pipe bolts at the catalytic converter using a socket set.
  3. Carefully detach the catalytic converter from the exhaust system.
  4. Inspect the old catalytic converter for any signs of internal damage or blockage.
  5. Install the new catalytic converter, ensuring the gaskets are in place to prevent leaks.
  6. Tighten all bolts to the manufacturer’s specified torque settings.

4. Clear Codes and Test

• Sub-steps:
  1. Reconnect the battery terminal and ensure all tools are removed from the engine bay.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the engine and allow it to reach operating temperature.
  4. Test drive the vehicle under various conditions to ensure the check engine light does not reappear.