small miss, somthin simple!!!!!

Cars running 100% but when i rev it up and take your foot off and rev it again, as if you wer dabbing it through the gear change lets say, it dies abit then reves as normal , its like its struggling a little, would it be drawing air from somewer cause it? checked everything and everythin an the car is brand new, its just annoying more than any thin, mabey is it running rich or somthing, anyone help???