my Honda Civic 11th Generation (2022-Present) has a P0420 code how to fix it

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to avoid electrical hazards.
• Elevate the vehicle securely on jack stands if working underneath.

2. Inspect and Clean Oxygen Sensors

• Tools Required: O2 sensor socket, brake cleaner.
• Steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Remove the sensors using the O2 sensor socket.
  3. Clean the threads of the sensors with brake cleaner.
  4. Reinstall the sensors, ensuring they are torqued to the manufacturer's specifications (typically around 30 ft-lbs).

3. Check and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, pry bar, cutting tool (if necessary).
• Steps:
  1. Inspect the catalytic converter for signs of damage or blockage.
  2. If replacement is necessary, unbolt the catalytic converter from the exhaust system.
  3. If welded in place, carefully cut the converter out using a cutting tool.
  4. Install the new catalytic converter and bolt it securely, using a torque wrench to ensure proper tightness.
  5. Reconnect any exhaust hangers and ensure the exhaust is properly aligned.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Perform a test drive to ensure that the vehicle operates normally and the check engine light remains off.