I don't have your engine info, but some are just a rubber tube from the engine, or valve cover, to the air cleaner housing. Other have a plate, with the tube, mounted to the engine that can be removed. Under the plate is a rubber diaphragm that should be cleaned and its functionality checked. On this type, I would replace the diaphragm and the tube if necessary. I'm thinking that if this is bad, it may cause back pressure in the engine.
