I bought mine just to change the speedo with the bigger tires i have VERY EASY all I did was tires nothing else it disconnected my front swaybar. I changed all switches to the stock default, plugged back in everything went back to normal and the speedo stayed correct. VERY HAPPY VERY EASY

 

just wondering, when you use it to correct for the tire size and gear swap, does it correct the odometer as well? or just the speedometer and trans shift points?