Excuse my terrible mechincal terms here!! Where the injector housing lives (on top of the airbox) there is a kind of gasket that seperates the injector box from the airfiler box. Its held on by about 6 x 8mm bolts. The gasket there about 6-7" long and 3-4" wide. My gasket looks like its had it. If it has had it is it essential that its replaced?