Sudafed (edit: also) makes (or at least made) products with phenylephrine, the useless drug in question. Those products don't contain pseudoephedrine, which can indeed be used as a precursor to making meth.

Edit: I did not say that Sudafed did not also make products containing pseudoephedrine. They do, obviously, it's where their name comes from. They just also make products with useless phenylephrine.