Vacuum hose: help with part number?

Hayes hose mfgrs calls this emission hose . It's made to stand up to the filth that's in EGR and all of that kind of nastiness coming out of a valve cover It is especially made for this and it comes in a bunch of different sizes that's usually when discussed the size is talking about the hole in the middle which is going to push over the barb fitting in your device car or whatever You could call the Toyota dealer and they could tell you what this hose would cost from them they probably won't have it but absolutely I don't have the parts break down to tell you but gates corporation should be able to provide you with more information than you might want It's pretty common hose pretty common engine It's the same as a Corolla for the most part.

 

My guess is it's the fuel vapor supply hose.
23826-37090

 

It splits because emission has has dried the hose out . New hose is pliable old not sooo much

 

Tediously “out of stock” here:

https://www.amayama.com/en/genuine-catalogs/epc/toyota-usa/prius/ZVW30L/12384/engine/1708

Look for comparable aftermarket, by-the-foot, “fuel vapour” hose? It won’t have the preformed elbows, but should still work.