on ya power fc u can display all sorts of readings, i display speed, revs, water temp, injector duty, timing and knock reading
the knock sensor reads small amounts of detonation and is displayed by using numbers, i think the most u want 2 see is no more than 60 (not sure) if u give it 2 much throttle and the detonation reads higher your engine warning light will flash, the knock reading can be reset on ya controller, mine doesnt get any higher than 12-25 on boost n about 7 off boost