Well i got a dyno tune today. The car ran great on the drive home for the first hour. While driving at 70mph, i tried to pass someone, the trans geared down fine, accelerated fine, then it wouldn't up shift. It stayed in the lower gear until i let off the gas completely. Then as soon as i touch the gas pedal ever so slightly the car gears down instantly and wont up shift again until i let completely off. I exited at the nearest ramp and stopped. accelerating from stop, the car just wouldn't shift right. It actually cut off when turning in to autozone. The code was p0121. Throttle Position Sensor/Switch A Circuit Range/Performance Problem. I purchased a Tps sensor, installed it there then cleared the code. I got back on 95 heading home. Everything seemed fine, i passed 3 or 4 people just like above with no issues. Then the next time i tried to pass the same thing happened. This time no code or check engine light...yet. I called the guy who tuned it, he went back to the shop and did some research on the code and feels what he did couldn't have caused it. Any Ideas anybody?
My mods are ZZP 3" Downpipe, PLOG, 3.4 pulley, 1.9 Rockers, Wizaired CAI, Magnaflows, 180Tstat, 104's. Thanks in advance for the help.