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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and engage the parking brake.
• Disconnect the battery to avoid any electrical issues.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the pre-catalytic oxygen sensor using the O2 sensor socket.
  • Sub-steps:
    • Unplug the sensor connector.
    • Use the sensor socket to unscrew the sensor from the exhaust manifold.
• Install the new oxygen sensor by reversing the removal steps.
  • Ensure: Torque the new sensor to manufacturer specifications.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, torque wrench
• Raise the vehicle using a jack and secure it with jack stands.
• Disconnect the exhaust pipes before and after the catalytic converter.
  • Sub-steps:
    • Remove any bolts or clamps securing the catalytic converter.
    • Carefully pull the old catalytic converter out.
• Install the new catalytic converter.
  • Ensure: Use new gaskets and torque all bolts to specifications.

4. Clear Codes and Test Drive

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code and any other stored codes.
• Start the engine and allow it to reach operating temperature.
• Take the vehicle for a test drive to ensure the check engine light does not return.