I wouldn't bother. The actual cell is post downstream O2 sensor meaning you'll get a engine management light on if you're not remapped. Quality won't be good either, much better off saving a bit extra and getting a pair from one of our preferred suppliers
https://www.tarmacsportz.co.uk/tarmac-sportz-nissan-350z-vq35de-03-06-high-flow-cats-hfcs-sports-cats.html?gad_source=1&gclid=Cj0KCQiA7OqrBhD9ARIsAK3UXh37Np-S9RpUry2HphIhXPkXcFpTQi2AQdukm0nYUxivI3Q-XPt5X-4aApVfEALw_wcB
https://www.torqen.uk/nissan/350z/exhausts/high-flow-cats/62687-350z-de-z33-torqen-high-flow-cats.html