Hey Ray, I apologize you had a a rough time at the shop this is Mary, David's wife I am not entirely sure how to use this review thing but I wanted to respond for you.
I would like to tell you sorry so the reason the sensor was back in your vechile was in hopes you could get your money back, the tire tech did not clarify with the girls properly the sensor was not putting out enough mega hertz to get a actual reading on the tire / vechile with the sensors won't properly communicate with the program tablet it won't allow proper reads which will cause an error. the tpms tablets have really come along way now yes sir we can check the sensors before install now to make sure they are functioning. I am very sorry you had such a hard time up at the shop I personally apologize I wasn't there to help out and clear things up. Hopefully if you would like to keep coming next time will be 10 fold a better experience.