MSsub22

well i have a 2001 impreza sedan L 2.2 N/A, ive been noticing that when i get to around 3.8-4.6 rpm it hesitates, mainly in 3rd and 4th gear, i have all new spark plugs, and my wires are relativley new, i have an ingen intake and a custom exuast 2 1/4 IN piping, im not sure if maybe one of the 2 is throwing it off, but when i changed out the spark plugs this summer one of them had like this white cystal like build up on it.