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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level 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, multimeter
• Remove the upstream oxygen sensor using the O2 sensor socket.
• Install the new upstream oxygen sensor and torque it to the manufacturer's specifications (usually around 30 ft-lbs).
• Repeat the process for the downstream oxygen sensor if it is also faulty.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary)
• Remove any heat shields or brackets obstructing access to the catalytic converter.
• Disconnect the exhaust pipes connected to the catalytic converter. Use an exhaust pipe cutter if needed.
• Remove the catalytic converter from its mount using a socket set.
• Install the new catalytic converter and ensure all bolts are tightened to the manufacturer’s torque specifications.
• Reconnect any removed heat shields or brackets.

4. Clear the Codes

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code from the system.