Unknown plug goes where?

[roadboy]

hey, i recently found this plug under the afm, traced it back to the coolant neck area. heres a pic, anyone know where it goes?
Thanks.

 

[carter]

if i remember right it goes to the coolant neck. if you have a further away picture i might be able to help.

 

[san supra]

this one? i had the same question but ive ran without it with no problem

 

[roadboy]

yes!!, that one..sorry for the crappy pic, it was a cell pic.
anyone know where it goes? or its always unplugged?

 

[aznboik1mva]

dude i jus left it unplugged, my car runs fine no check engine light.