Problem with my Gt
 

Well i have a couple of problems with my mustang. WHen i punch it somtimes when it changes the gear it whistles weird no its not supercharge. Also when im at park and i hit reverse at times it just goes like if i hit the gas hard but i haent even touch the gas it just goes by itself, i believe theirs something wrong with the tranny i dont know. Also at take offs its super slow which i dont know why....? i had it tuned up already. sometimes when its changin gears it like stutters or somethign can anyone tell me what might be wrong with my mustang thanks!

Could possibly have a bad tune for your vehicle. Try switching back to the stock tune and see how it runs.

when i got my car i noticed that also. but then i started too watch my rpms when i would go from drive to reverse or park to reverse and sometimes the rpms would drop below 500 and im assuming that the computer compensates for you and feeds your car gas explainning the why your car jumps. this doesnt happen all the time but mine still does it every now and then. those other problems that your having i dont know what to tell you.