2005 Impraza 2.5rs Dictator management.

Good day everyone. 

I need some advice. I recently baught a 2005 impreza 2.5rs and she is running on a dictaror ecu. Currently i have an engine light blinking. I took it to get it diagnosed. The diagnostic machine picked up its the knock sensor and 1 abs sensor. I took the car inbfor a major service and they advised me that the dictator doesnt use the knock sensor. Im not to sure how true this is. If so how do i permanently clear the fault code ?

Any advise would be appreciated.