my Honda CR-V check engine light is on with code P0420, what does it mean?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on the vehicle.

2. Inspect Oxygen Sensors

• Remove the upstream (pre-catalytic) oxygen sensor using a socket wrench.
• Check the sensor for damage or contamination. Replace if necessary.
• Reinstall the sensor and torque to manufacturer specifications.

3. Examine Catalytic Converter

• Raise the vehicle safely on jack stands.
• Inspect the catalytic converter for any signs of physical damage or rattling.
• If damaged, remove the catalytic converter by unbolting it from the exhaust system using a socket set.
  • Note the orientation of the old converter for correct installation of the new one.
• Install a new catalytic converter and tighten bolts to the manufacturer's torque specifications.

4. Reinstall and Test Oxygen Sensors

• If the downstream (post-catalytic) oxygen sensor was removed, reinstall it in the same manner as the upstream sensor.
• Ensure all electrical connections are secure.

5. Clear Codes and Test Drive

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and allow it to reach operating temperature, then take the vehicle for a test drive to confirm that the check engine light does not reappear.