When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
To answer your question, yes you need it. It is a PCV valve (positive crankcase ventilation). It is a part of the pollution controls and it is supposed to put oil into the intake. It takes crankcase gasses (blow by) and routes them to the intake to be burned instead of venting to the atmosphere.
