I have an '06 GT with Kooks headers, catted x-pipe, Detroit Rocker cams, FRPP intake and throttle bottle, C&L Racer intake, Brenspeed 93 octane tune, and Performance Automatic 2800 RPM torque converter. For about the last 8 months I've had an issue where, when starting the car in cold or wet conditions, if I shift into drive without letting the engine idle and warm for several minutes the engine will die. It then requires throttling the engine to get it started and it runs rough, requiring me to feather the throttle for a few seconds until the engine smooths out. Today, in sunny, 50 degree conditions, it took me probably a dozen starts before the idle smoothed out and I could take off. This time, the engine would even choke and die in park unless I throttled it. Upon starting, it would release a cloud of smoke and the exhaust had a pungent, sharp smell. It will also smell slightly of fuel. Ordinarily I would think it was a fuel issue, but I'm not getting any check engine lights. Could this be an issue with the tune? I'm running stock style flags with stock gap, and factory injectors and oxygen sensors.