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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the threads and connectors for damage; replace any faulty sensors with new OEM parts.
• Install the new oxygen sensors and torque to the manufacturer's specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting torch or exhaust pipe cutter (if necessary), torque wrench
• Locate the catalytic converter and inspect for physical damage or excessive carbon buildup.
• If replacement is needed, disconnect the exhaust pipes at both ends of the catalytic converter.
• Remove the catalytic converter and install a new one, ensuring proper alignment.
• Torque all connections to manufacturer specifications.

4. Clear Codes and Test Drive

• Reconnect the battery and use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Perform a test drive under various conditions to ensure the check engine light does not reappear.