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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Infrared thermometer
• Multimeter

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Using the socket wrench, carefully remove the oxygen sensors from the exhaust system.
3. Inspect the sensors for damage or carbon buildup.
4. Replace with new OEM or equivalent sensors if necessary.
5. Torque the oxygen sensors to the manufacturer’s specifications (generally around 30 ft-lbs).

3. Inspect and Replace the Catalytic Converter

1. If the catalytic converter is damaged or has failed, remove the exhaust components leading to it.
2. Use a socket set to unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
3. Inspect the gasket surfaces for damage and clean as necessary.
4. Install the new catalytic converter with new gaskets, ensuring proper alignment.
5. Torque bolts to manufacturer specifications (generally around 40-50 ft-lbs).

4. Clear Codes and Test Drive

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code.
3. Test drive the vehicle to ensure the check engine light does not reappear and that the vehicle operates smoothly.