I finished an ECM flash on a 08 C6 LS3 and went for a test drive. the car at a stop will stumble and jerk as the HUD shows the gear position going from 1st to 2nd then 3rd and back to 2nd the whole time at a stop. as soon as I take off it will snap into 3rd then quickly into 4th and hold it. i floored it and it only speeds up in 4th and the paddles will not let me up or down shift? I did nothing with the TCM. I used V2 w/ 7.5, 83 build - E38