hi i need some info on what pipes go where on a sportrak. i have one missing. if u look into the engine bay there are 4 outletson top of the inlet manifold on my car its silver. on mine there is 1 ontop and 3 under it, all 3 of the bottom ones have pipes on them but the top one does not.

so my question is should it have a pipe and if so where does it go to does anyone no what it does plus will it affect my mpg as its not great at the moment.

thanks guys