how to fix Honda Civic 11th Generation (2022-Present) P0420 code for catalytic converter

Solution

1. Preparation

• Gather tools and materials.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the battery for safety.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors in relation to the catalytic converter.
2. Using an O2 sensor socket, carefully unscrew and remove the faulty oxygen sensors.
3. Install new oxygen sensors, ensuring they are properly threaded and torqued to the manufacturer's specifications (typically around 30 lb-ft).
4. Reconnect the wiring harness to the new sensors.

3. Inspect and Replace Catalytic Converter

1. Remove any heat shields or protective covers over the catalytic converter using a socket set.
2. Disconnect the exhaust pipes from the catalytic converter by removing the bolts or clamps.
3. Remove the old catalytic converter from the vehicle.
4. Install the new catalytic converter, ensuring it aligns properly with the exhaust system.
5. Reattach the exhaust pipes and secure them with the appropriate torque (typically around 40 lb-ft).
6. Reinstall any heat shields or protective covers that were removed.

4. Clearing the Code

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code from the system.
3. Start the engine and allow it to reach operating temperature.