I had the same problem. I checked all my connections 3 to 4 times. It would rev only to about 3000RPM and the idle was really rough. I unhooked the box and it ran fine. I sent the box to Vortech and two days laster they sent it back reprogrammed. Worked fine. I don't have an A/T though. You might want to call them first, but I know there was another person that had the same problem.