all of the impreza (except for some rare model naturally aspirated mounting hitachi) mounts ecu denso. WRX and STI are read only interface openport 1.2 or 2.0 depending on the year of the machine. To map or ecuflash or ecuedit... the diesel reads/writes also kess v2, but returns a partial file (1,5 mb compared to 2 mb of openport or magpro x17/fpv)...