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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Tools Required: OBD-II scanner, multimeter, jack and jack stands, socket set, torque wrench, exhaust pipe cutter, and safety glasses.
• Parts Required: Catalytic converter (if necessary), oxygen sensors (if faulty), exhaust gaskets.

2. Address Any Exhaust Leaks

1. Raise the vehicle securely using a jack and jack stands.
2. Inspect the entire exhaust system for leaks, focusing on joints and connections.
3. If leaks are found, repair or replace the affected components (e.g., using exhaust tape or welding).
4. Recheck for any codes after repairs.

3. Replace Oxygen Sensors (if faulty)

1. Locate the upstream and downstream oxygen sensors.
2. Disconnect the electrical connectors from the sensors.
3. Use a socket wrench to remove the sensors from the exhaust system.
4. Install the new sensors by reversing the removal steps, ensuring they are torqued to manufacturer specifications.
5. Reconnect the electrical connectors securely.

4. Replace Catalytic Converter (if necessary)

1. If the catalytic converter is deemed faulty after testing, mark the positions of the exhaust pipes for alignment.
2. Use an exhaust pipe cutter to remove the old catalytic converter.
3. Clean the mating surfaces on the exhaust pipes.
4. Install the new catalytic converter, ensuring proper alignment with gaskets.
5. Torque the bolts to manufacturer specifications, typically around 20-30 lb-ft.
6. Reinstall any heat shields or protective covers.