Hello! I recently bought a 2004 Mustang GT 4.6L. When I bought it I was given a BAMA tuner with some box tunes on it. With those tunes, it would cause the rpm to hang around 3k rpm, hold there until I stopped and it would kill the car. After doing some research I have gathered that BAMA box tunes aren't the greatest. I returned the vehicle back to stock and didn't have that problem since then. I recently took it to get dyno tuned thinking that if it was a custom tune the problems would stop. Well, unfortunately that isn't the case. The throttle gets stuck and in 5th gear it'll drive itself at about 50mph. When I push in the clutch the engine is at a Rev of about 3k rpm and will stay there until I stop and the car kills itself. Further more, normally after this happens and I start the car back up it'll start drop to idle and kill itself again! Anybody have any idea how to fix? This seems to be caused by the tune somehow and have no idea what it could be. I've searched high and low on forums and nobody seems to be having quite the issue like I am having.

It tends to get stuck most frequently when casual driving. It will get unstuck occasionally if I push in the clutch and Rev the engine pretty good and it'll idle and drive normal there after.