i believe there are many, in similar years, that have identical ps caps, like altima. not sure how many models would be the same, but it is one of the universal sizes for nissan. just bring your old one into the yard so you can part match. if its the same diameter, it should fit.
you did try cleaning the seal, and putting some of the ps fluid on the rubber to see if it does seal? made sure it wasnt cracked somewhere?