how to clear the P0420 code on Honda Accord 8th Generation (2008-2012)?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical issues during repairs.
• Allow the engine to cool down before starting work.

2. Inspect and Replace the Downstream Oxygen Sensor

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the downstream oxygen sensor from the exhaust pipe by turning it counterclockwise using an O2 sensor socket.
• Install the new oxygen sensor by threading it into the exhaust pipe and tightening it to manufacturer specifications (typically around 30-35 ft-lbs).
• Reconnect the electrical connector to the new sensor.

3. Inspect the Catalytic Converter

• Visually check the catalytic converter for any dents, rust, or signs of overheating.
• If damaged, remove the catalytic converter by loosening the bolts on both ends using a socket set.
• Install a new catalytic converter by reversing the removal process, ensuring all bolts are tightened to the specified torque (usually 25-30 ft-lbs).

4. Clear the Code and Test Drive

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Perform a test drive to allow the vehicle's computer to re-evaluate the system.