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

Solution

1. Preparation

• Gather required tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Raise the vehicle securely on jack stands if access to the undercarriage is needed.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Use a socket wrench to remove the oxygen sensors from their respective locations.
3. Inspect the sensors for signs of damage or contamination. Replace if necessary.
4. Install new oxygen sensors, tightening to the manufacturer's specified torque (usually around 30 lb-ft).
5. Reconnect the battery.

3. Catalytic Converter Inspection and Replacement

1. Inspect the catalytic converter for physical damage, such as dents or rust.
2. If replacement is required, disconnect the exhaust system from the catalytic converter by loosening the bolts or clamps.
3. Remove the old catalytic converter and install the new unit, ensuring proper alignment and sealing.
4. Tighten all connections to the specified torque (usually around 20-30 lb-ft).
5. Reinstall any heat shields or protective covers that were removed.

4. Clear Codes and Test Drive

1. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
2. Start the engine and let it reach operating temperature.
3. Take the vehicle for a test drive to ensure the check engine light does not reappear and the vehicle runs smoothly.