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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical issues.
• Raise the vehicle using a lift or jack stands to access the exhaust system.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, wrench set, multimeter
• Remove the upstream oxygen sensor using the O2 sensor socket.
• Inspect the sensor for damage; if it is faulty, replace it with a new one.
• Repeat the process for the downstream oxygen sensor if it is also found to be defective.

3. Replace Catalytic Converter (if required)

• Tools Required: Socket set, wrench set, exhaust pipe cutter, gasket scraper
• Remove the bolts securing the catalytic converter to the exhaust system using the socket set.
• Carefully detach the catalytic converter from the exhaust pipes.
• Clean the mating surfaces of the exhaust pipes to ensure a good seal.
• Install the new catalytic converter, ensuring the correct orientation, and secure it with bolts.
• Torque the bolts to the manufacturer's specifications (typically around 30-40 ft-lbs but check specific requirements).

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Start the engine and allow it to idle for a few minutes.