Fellow 997 turbos...I have an 2007, and I am looking for help. When in sport mode, in 2nd gear, 3rd gear around 2200-3000 rpm, when letting off the throttle, I feel a surge of power. Diverter valve was replaced, throttle body was replaced, as both were needed to be replaced. Had a recent engine out to address coolant lines and checked for vacuum leaks, and found no leaks. What are we missing? Thoughts?