how do I fix the P0420 code on my Honda Pilot Third Generation (2016-present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down completely.

2. Inspect and Repair Exhaust System

• Tools Required: Socket set, exhaust pipe cutter (if applicable), exhaust sealant.
• Inspect all exhaust pipes for cracks or holes. Repair or replace any damaged sections.
• Ensure all exhaust gaskets are intact and replace if necessary.

3. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, torque wrench.
• Disconnect the electrical connectors from the upstream and downstream oxygen sensors.
• Remove the faulty sensors using the O2 sensor socket.
• Install new sensors and torque to manufacturer specifications (usually 30-35 lb-ft).
• Reconnect the electrical connectors.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, exhaust pipe cutter, new gaskets.
• Support the vehicle with jack stands and remove the exhaust components leading to the catalytic converter.
• Cut the exhaust pipe if necessary, using an exhaust pipe cutter.
• Remove the old catalytic converter and install the new one with new gaskets.
• Reattach all removed exhaust components and ensure they are secured and leak-free.

5. Reset the Engine Control Module (ECM)

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the ECM.