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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Allow the vehicle to cool down before beginning work.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench, multimeter.
• Use a multimeter to test the voltage output of the upstream and downstream oxygen sensors. If low or erratic, replace the faulty sensor.
• Disconnect the electrical connectors from the oxygen sensors.
• Remove the sensors using the O2 sensor socket and install new sensors, ensuring they are properly torqued according to manufacturer specifications (typically 30 lb-ft).
• Reconnect the electrical connectors.

3. Inspect Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter (if needed).
• Check for any physical damage or blockages in the catalytic converter.
• If damaged, remove the catalytic converter by loosening the bolts and cutting any welded sections if necessary.
• Install a new catalytic converter, ensuring all connections are secure and properly torqued.

4. Clear the Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and allow it to reach operating temperature.
• Conduct a test drive to ensure the code does not reappear.