Local Mazda Dealership sent home their recommendations to a widow woman at my office for her 2013 Mazda 3 Skyactiv car for a fuel injection system flush for $125. She asked me if it was needed and I told her that it would be something I would probably pass on if it did not effect her warranty. From my understanding the Direct Injection do not really benefit from such procedure and that carbon build up is in an area behind the valves that this type of flush would not reach. I am hoping that my advise was appropriate but thought I might check with others on this board who might have a Mazda or Direct Injection experience.