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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

1. Remove the Negative Battery Terminal: Use a socket set to disconnect the battery to avoid electrical shocks.
2. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
3. Unplug the Sensors: Carefully disconnect the electrical connectors from both oxygen sensors.
4. Remove the Sensors: Use an oxygen sensor socket to unscrew and remove the sensors from their respective locations.
5. Install New Oxygen Sensors: Apply anti-seize compound to the threads of the new sensors and install them securely. Do not overtighten.
6. Reconnect Electrical Connectors: Plug the connectors back into the new sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Check for Blockages: If the catalytic converter is clogged, it may need replacement.
2. Remove Exhaust Components: Use a socket set to detach any exhaust components connected to the catalytic converter.
3. Remove the Catalytic Converter: Unscrew the catalytic converter from the exhaust manifold and the exhaust pipe.
4. Install New Catalytic Converter: Position the new catalytic converter in place and secure it with the appropriate hardware.
5. Reconnect Exhaust Components: Reattach any exhaust components that were removed.

4. Final Checks

1. Reconnect the Battery Terminal: Reconnect the negative battery terminal securely.
2. Clear the Code: Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.
3. Test Drive the Vehicle: Take the vehicle for a test drive to ensure the issue is resolved.