what does it mean if my Honda Pilot YF3 (2016-2022) has a P0420 code

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Use a socket wrench to remove the oxygen sensors.
3. Inspect the wiring and connectors for damage; replace if necessary.
4. Install new oxygen sensors and tighten to manufacturer specifications (typically around 30 Nm/22 lb-ft).
5. Reconnect the battery.

3. Inspect and Replace Catalytic Converter

1. Remove any heat shields or brackets securing the catalytic converter.
2. Disconnect the exhaust pipe from the catalytic converter using a socket set.
3. Remove the old catalytic converter by unbolting it from the exhaust manifold.
4. Install the new catalytic converter, ensuring proper alignment and sealing.
5. Reattach exhaust components and any heat shields removed earlier, tightening bolts to the specified torque.

4. Clear Codes and Test Drive

1. Reconnect the OBD-II scanner to clear the P0420 code from the ECM.
2. Start the vehicle and allow it to reach operating temperature.
3. Take the vehicle for a test drive to ensure the check engine light does not reappear.