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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shock.
• Ensure the engine is cool before starting work.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the threads and wiring for any signs of damage.
• Install new oxygen sensors, tightening them to the manufacturer's torque specifications (typically around 30 lb-ft).

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter, new gaskets and bolts
• Remove the exhaust pipes connected to the catalytic converter using the socket set.
• Cut the exhaust pipe if necessary to remove the old catalytic converter.
• Clean the exhaust flange surfaces to ensure a proper seal.
• Install the new catalytic converter with new gaskets and bolts, tightening to the manufacturer's specifications.

4. Clear the Codes

• Reconnect the vehicle battery.
• Use the OBD-II scanner to clear the P0420 code from the system.

5. Test Drive

• Take the vehicle for a test drive to ensure the repair was successful and that the check engine light does not reappear.