well today on the way to work i gave it a little bit of welly down a dual carriage way and as my car got to about 3-4k rpm its like it hit a big flat spot and was definately misfiring and boost dropped off, now every time it hits 3k rpm at WOT it does the same, pulls really nicely up til then though! im thinking plugs? its not long had all 4 coilpacks done. are there any sensors that can be replaced just to eliminate them as a possibility? cheers in advance!