I recently bought a 2001 Mustang Bullitt with 3.73 gears installed in it. I have a Predator handheld that came with the ATI Procharger kit and it will not recalibrate the speedo even though it says it does when I modify and install the tune. I have also tried changing the tire revolutions per mile setting also and it doesnt do anything either. Is this a common problem with these programmers? What do I need to do to get it fixed?