Yes, I have not used colortune, its a cool idea but it seems to have some pretty obvious flaws. I think it is great for tuning idle fueling, but really tuning fueling for any other throttle position is out of the question or unsafe. Unless you have a dyno. But then, if you have a dyno you likely have O2 sensors, making the colortune redundant. Just my thoughts, having not used the system.