2015 Mustang pulls to the right during acceleration

Hey all, new to this subreddit, but I was driving on a highway when I was overtaking a car, a muffler came out of nowhere and I hit it. Caused a flat in my back left. Now whenever I accelerate, my car pulls to the right, and then back to normal when i let off the gas. I read some place that it could be the rear diff not centered. I don't know if it is the IRS (independent rear suspension) but I have to eliminate all possibilities. Especially after spending money on the new tire and all that fun stuff. Also, I bought the car about 3 weeks ago and I don't know exactly what has been done to the car but I am starting to wonder if maybe the upper or lower control arm got messed up because the angle on my right side is now much more after hitting that muffler in the road, compared to my left side. Thanks to any that help.