how to fix Honda Pilot YF4 (2023-Present) P0420 code for catalytic converter

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the exhaust system to cool before working on it.

2. Replace Faulty Oxygen Sensors (if needed)

• Remove the upstream and downstream oxygen sensors using an oxygen sensor socket.
• Install new oxygen sensors and torque them to the manufacturer's specifications (typically around 30-40 ft-lbs).
• Reconnect the electrical connectors to the sensors.

3. Inspect and Replace the Catalytic Converter (if needed)

• Raise the vehicle securely on jack stands.
• Remove any heat shields or brackets obstructing access to the catalytic converter.
• Unbolt the catalytic converter from the exhaust system using a socket set, taking care to keep any gaskets or seals.
• Install the new catalytic converter, ensuring it is oriented correctly and all gaskets are replaced.
• Torque the bolts to the manufacturer's specifications (typically 15-25 ft-lbs for exhaust bolts).

4. Reassemble and Reconnect

• Reinstall any heat shields and brackets that were removed.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.