sorry, i didnt't write it too clearly , my bad
umm.. does ur boost/vac guage show that your reading less vaccumm?while the car is idling pop your head under the bonnet,if u can hear hissing or a whistle sound try to track it down. move around the vacc hoses and put your hand over the joiners.if you find a suspect spot then grab a can of aerostart and spray it on it.if there's a hole the aerostart will get sucked into the intake and u will hear the idle rise for a second as the aerostat burns off..