how to fix Honda Pilot Third Generation (2016-present) P0420 code

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and securely raise the vehicle with jack stands.
• Disconnect the negative battery terminal to ensure safety while working with electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, OBD-II scanner
• Remove the upstream oxygen sensor from the exhaust manifold using the O2 sensor socket.
• Inspect the sensor for carbon buildup or damage; replace if necessary.
• Repeat the process for the downstream oxygen sensor located before the catalytic converter. Replace as needed.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter, torque wrench
• Inspect the catalytic converter for signs of clogging or physical damage.
• If replacement is necessary, use an exhaust pipe cutter to remove the old catalytic converter from the exhaust system.
• Install the new catalytic converter in the same position, ensuring proper orientation.
• Use a torque wrench to tighten all connections according to the manufacturer's specifications.

4. Reset the Engine Control Module (ECM)

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and let it idle for a few minutes to ensure the system is functioning correctly.