boost leak

Hey SpoolStreet! I'm fully new to this group and ready to discuss something that has been going on with my 07 335i e90. Recently, my 335i all suddenly started to not make much power and have been noticing at 2-2.5k RPM the whole car shutters and shakes struggling to hold power or something...

HELLO NEW TO THE BMW WORLD SO PLEASE BARE WITH ME ON WHAT IM GOING THRU.. SO IVE ONLY HAD THIS CAR FOR ABOUT A YEAR NOW AND THERE WAS UPGRADES DONE ON IT BEFORE HAND AND RECENTLY I HAVE WENT THRU IT AND NOTICED FEW THINGS NEEDED TO BE ADDRESSED RADIATOR HOSE,OIL FILTER HOUSING GASKET, MAIN BELT...