Generation IV Internal Engine - ls2 problem

My lS2 is giving me problems between 4800rpm to 5500rpm when I shift from 2nd to 3rd. It feels like my motor is running on half the motor but then after 5500 it feels strong again. It doesnt always do this. aNY IDEA?

tune?

The tune seems fine. I looged it and did a a/f and it was fine but I also did that when it was cool out. Could it be the heat soaked problem being the filter is exposed to the hot engine heat?