There is probably a good reason that we dont use these that will be made very clear in this post. I was just increasing my knowlege on import cars and the things that they use and mod with. One thing that caught my eye was the AFC...Air/Fuel Controller. From what I could figure out, this thing does the same thing as the MAFT, but it does it automaticly and in real time, by tying in to the O2 sensors, Throttle position sensors and the MAF readings, it manipulates air and fuel data to make the car run stoich.....am I right in my assement of this piece of equipment? If I am, it sounds awesome...why dont we use it to make sure our cars dont run too lean or too rich?