There are two hoses, both rubber. One goes under the fuel distributor, the other under the intake manifold. Can't miss em
I would take the opportunity regardless and remove the ICV, shoot it with carb cleaner completely (I bet ya you'll be surprised how brown the fluid will come out) then replace BOTH hoses. If you haven't done them yourself, its time. Follow this guide for the most difficult (intake side) this trick will save you a lot of time:
http://www.w124-zone.com/articles.php?article_id=35