how to fix P0420 code in my Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather all tools and parts needed for the repair.
• Disconnect the vehicle battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the electrical connectors from the sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust pipes.
  4. Install new oxygen sensors and torque them to the manufacturer’s specifications (typically 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed).
• Steps:
  1. Raise the vehicle securely on jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Remove any clamps or bolts securing the catalytic converter to the exhaust system.
  4. Inspect for any damage; if defective, remove the old catalytic converter.
  5. Install the new catalytic converter, ensuring proper alignment and securing it with bolts or clamps.
  6. Torque bolts to manufacturer specifications (typically around 20-30 lb-ft).

4. Clear the Codes

• Tools Required: OBD-II scanner.
• Steps:
  1. Reconnect the vehicle battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.