If it isn't working, it isn't hurting nor helping things.
Hardest part is removing the AIR manifolds from the exhaust manifolds, in many cases the fittings simply break and there isn't an easy way to get them out. If you can unthread all of them, some brass pipe plugs work good enough to seal the ports up.
Typically this sort of stuff is expensive to replace, if certain parts are in good shape, you might want to hang onto them in case you have the truck long enough to see emissions inspections come to your area and need to put it back. Even if not, if you ever sell the truck, if the potential buyer lives in an emissions inspection area, that will make selling it harder.
