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

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shorts during repair.
• Allow the engine to cool before starting work on the exhaust system.

2. Inspect and Replace Faulty Oxygen Sensors

• Locate the upstream and downstream oxygen sensors.
• Use an O2 sensor socket to remove the faulty sensors.
• Install new oxygen sensors, ensuring they are torqued to the manufacturer’s specifications (typically around 30 ft-lbs).
• Reconnect the electrical connectors.

3. Examine and Replace the Catalytic Converter

• Remove the exhaust heat shield if applicable.
• Use a socket set to unbolt the catalytic converter from the exhaust system.
• Carefully remove the old catalytic converter.
• Install the new catalytic converter, ensuring all gaskets are in place and torqued to manufacturer specifications.
• Reinstall the exhaust heat shield if removed.

4. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.