My 2010 and my current 2012, both PP cars, have had the same issue. Including when traction control etc was off. I used Forscan a few days ago to look at the desired torque converter slip vs actual slip and it's as if the TC doesn't want to release causing the motor to lug and thus have that throttle lag. I'm off on Friday so taking it by a reputable trans shop to get an idea of whether or not its a sensor, solenoid or worse. Hoping it's simple. This 2012 was a one owner, local trade and drives like it's brand new otherwise. I'll also add that in both cars I had good luck alleviating some of the issue by calibrating the throttle (car on, engine off, press throttle all the way down, car off, rinse and repeat a few times) and adding wire loom to the knock sensor wires. The 2012 knock sensor wires look fine but damn if the car didn't wake up quite a bit after just moving the wires from touching the head. I believe later model years addressed the knock sensor wire problem but worth checking out. Spark plugs are another common issue as the Ecoboost motors all seem to eat plugs at lower than expected intervals.