Contour Enthusiasts Group Archives Forums General Troubleshooting Codes 172,176

Based on my scanner both codes indicated Lack of heated oxygen sensor switches indicate lean bank 1 and bank 2,would that means I have to replace two sensors,which side is bank 1?

Check for a vacuum or intake leak first. You may find something that doesn't cost much money to repair.

Depending on your mileage, you may have weak O2 sensors.

Bank 1 is the firewall side, bank 2 is the radiator side.

There are pleny of recent posts in the Duratec maintenance sction on how to replace the rear sensor.

Steve