Originally Posted by PAULW

I have not tried to read the XF computer but it very well may record information on the car when the check engine light comes on. There are ECM's that record data such as engine over-speed and absolute overheat but the Sprint Booster will not cause that, those issues are caused by driver error. Also the SB cannot be seen by the computer because it does not report to it and it can't be seen by the tech who by the way if he did see it would probably think it belonged there.