Where is the charcol cannister located under the xterra on 2002 Nissan Maxima

I have a po447 code. Do I have to replace the the control vent valve and how difficult is it. The dealer quoted me 350-400 here in Hawaii..I am getting conflicting The light came on about 2 days ago and runs fine presently.

Asked by for the 2002 Nissan Maxima