Hey guys, hopefully someone has had this problem before and knows what it is.

This started happening yesterday all of a sudden. When I drive lightly around town, completely normal. When i drive at WOT the car accelerates normally ( i am boosting about 16psi). When I drive the car under 'partial' acceleration with the gas pedal about half way down, my boost starts to rise ( builds up to between 5-10 psi) and the car gets louder, everything 'sounds' like i am giving it some gas but it does not accelerate, it kinda hesitates as if something is slipping, almost feels like a slipping clutch. does anyone have any idea?

i ruled out the clutch, it feels completely normal, and all vacuum lines are fine. since it accelerates great under WOT I have no idea what could be causing this. I thought maybe the o2 sensor may be acting up because i noticed that even during light driving my air fuel guage is going over to rich when it used to just bounce around until i gave it a lot of gas. but i figured if it was my o2 sensor i would have a check engine light.
someone please help thanks!