what does it mean if my Honda Pilot YF4 (2023-Present) has a P0420 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the pre-catalytic oxygen sensor from the exhaust manifold by loosening it with an O2 sensor socket.
• Install the new oxygen sensor, ensuring to torque it to the manufacturer's specification (usually around 30 ft-lbs).
• Repeat for the post-catalytic oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter or reciprocating saw, gasket scraper.
• Remove the exhaust pipe connected to the catalytic converter by loosening the bolts.
• Cut the exhaust pipe if necessary to remove the old catalytic converter.
• Install the new catalytic converter, ensuring that it fits properly and aligns with the exhaust pipe.
• Secure with bolts and replace any gaskets as needed.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals and ensure they are tight.
• Use an OBD-II scanner to clear the P0420 code from the ECU.