There are many wideband systems on the market today. What makes the NGK system better than the competition? What is included in the kit? What is the range of measurement for the AFX? Does the AFX have an analog output? Is the AFX compatible with leaded fuel? How long of a life can I expect from the sensor? Is the AFX compatible with fuels other than gasoline? My exhaust configuration makes it difficult for me to follow the sensor mounting guidelines listed in the manual. Will the system still work? During driving, my display sometimes jumps into calibration mode and reads Air_, Air¯, or CAL-. Is the unit malfunctioning?