I have a 2011 GT manual with a Bama tune and otherwise stock. I noticed that the car seems to be missing/surging around 2250RPMs. It does it in any gear. I've tried several tunes including there 91 and 93 octane performance tune and the 89 octane street tune. It seems the best with the street tune and the worst with the 91 performance tune. Anyone have a issue like this or any ideas?