I drive a 2006 mustang GT and ive had it for a while. recently it started to lag a bit, ill be driving and it will feel sluggish and then all of a sudden it will kick in and ill take off. it happens in different gears usually. What are some of the things that could be?

 

slipping trans, in need of tune up, better gas pedal control, or could be the throttle unit (since yours is by wire)

 

Thank you ^_^