how to diagnose P0420 code on my Honda CR-V Sixth Generation (2023-present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the vehicle to cool down before beginning work.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Use an O2 sensor socket to remove the faulty upstream sensor (if needed).
3. Install the new sensor, tightening it to the manufacturer's specified torque (usually around 30-40 lb-ft).
4. Repeat the process for the downstream sensor if it is also faulty.

3. Examine and Replace the Catalytic Converter

1. Remove the heat shields (if applicable) using a socket set.
2. Disconnect the exhaust pipes from the catalytic converter using a wrench or socket.
3. Remove the catalytic converter from its mounting brackets.
4. Install the new catalytic converter, ensuring a proper fit and alignment.
5. Tighten the exhaust bolts to the specified torque (usually around 30-35 lb-ft).
6. Reinstall any heat shields that were removed.

4. Clear Codes and Test Drive

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code.
3. Take the vehicle for a test drive to ensure that the check engine light does not reappear and that the vehicle operates smoothly.