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

Solution

1. Preparation

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

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream O2 sensor using the O2 sensor socket.
• Check the condition of the O2 sensor; if it is dirty or damaged, replace it with a new one.
• Install the new O2 sensor and torque it to the manufacturer's specifications (typically around 30 ft-lbs).
• Repeat the process for the downstream O2 sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if needed)
• Raise the vehicle using a jack and secure it with jack stands.
• Remove any heat shields and exhaust clamps securing the catalytic converter.
• Cut the exhaust pipes if they are welded and remove the old catalytic converter.
• Install the new catalytic converter, ensuring proper alignment with the exhaust system.
• Reattach heat shields and exhaust clamps, torquing them to specifications.

4. Clear the Code

• Tools Required: OBD-II scanner
• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the system.
• Perform a test drive to ensure the check engine light does not reappear.