Legacy F6-3.0L (2005)
Oxygen Sensor: Technical Service Bulletins
Engine Controls - DTC P2097 Information
11 P2097 AND REFLASHING
If you are reflashing a 2005MY Legacy/Outback, Forester, or Impreza, it is necessary to replace the front AF sensor when the ECM is installed back in
the vehicle. If you do not, there is a possibility the code will reset.