how to fix P0420 code on Honda Accord 8th Generation (2008-2012)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to avoid any electrical shorts.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Infrared thermometer
• Multimeter

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Disconnect the electrical connectors from both sensors.
3. Use a socket to remove the sensors from the exhaust system.
4. Install new oxygen sensors, ensuring to torque them to the manufacturer's specifications (usually around 30 ft-lbs).
5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if needed)

1. Remove any heat shields that may obstruct access to the catalytic converter.
2. Disconnect the exhaust pipes from the catalytic converter by removing the bolts or clamps.
3. Remove the catalytic converter by unbolting it from its mounting points.
4. Install the new catalytic converter, ensuring proper alignment and sealing.
5. Reattach the exhaust pipes and torque bolts to the specified values (typically between 30-40 ft-lbs, check manufacturer specs).
6. Reinstall any heat shields.