Just recently had my Shelby tuned with an SCT tuner. Car already has some work done... air intake, 3.73 gears, pulley, x-pipe/exhaust, dual cluch... but now it's lurching in every gear and won't idle down at the normal rate (lingers at 2000 rpm). Shop says it takes a break in period to adjust due to some learning the CPU needs to do but have any of you experienced this when tuning? How long did it last? It's been several hours of driving so far and no signs of changing.