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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to avoid electrical shock.
• Allow the engine to cool completely before proceeding.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Remove the upstream (pre-catalytic) oxygen sensor using the O2 sensor socket.
• Inspect the sensor for damage; if faulty, replace it with a new one.
• Connect the new sensor and torque it to the manufacturer’s specifications (typically around 30 ft-lbs).
• Repeat the same process for the downstream (post-catalytic) oxygen sensor.

3. Inspect Catalytic Converter

• Tools Required: Jack and jack stands, exhaust pipe cutter (if needed).
• Raise the vehicle securely using a jack and jack stands.
• Inspect the catalytic converter for physical damage, such as dents or visible rust.
• If the catalytic converter is damaged or clogged, remove it by cutting the exhaust pipes as needed.
• Replace it with a new catalytic converter designed for the Honda Pilot YF3.

4. Clear Error Codes

• Tools Required: OBD-II scanner.
• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Start the engine and allow it to reach operating temperature.