after dropping to a 3.5 pulley with a tune i have been having the same issue with my car, it hesitates and misfires under boost, it happens just on cyl 6 so i thought it was the EGR so i did the EGR blockoff since it dumped into cyl 6. but its still happening, what should i check next. i have also checked the coil packs, plugs and wires.