So, on my 2006 GT I've had some noticeable power loss. Just recently I installed offroad x pipes without the tune and drove about 50 miles total. After i installed it is noticed sputtering and some power loss that I actually felt in the pedal. I installed the tune, and the problem still exists. I don't pull as hard as I use too, every time I shift Ito seems like it bogs when I get on it, I don't know. Spark plugs? Coils? Fuel tank? I don't get misfire cels, but I have got 02 cels when this problem started. I did a pull today on reasonably slow GT and he whooped me! Can someone please help me out.