Car hesitates at 45 mph
 

Hey whats up guys im new to the mitsubishi world. I purchased a 2001 eclipse rs auto. While I'm driving the car shifts fine but when I'm coasting at around 45 mph it starts to hesitate and shake a bit for a quick second or two then i hit the gas and it goes away right away. I coast at different speeds and its fine. Any ideas what it could be? Hopeing its not the tranny cause im a college student and you know how that goes lol