On a 2000 max?

 

It's in the fuel tank; it's part of the fuel pump assembly.

Ain't that a *****?
Haven't changed mine yet myself... I intend to soon though. The fuel pump is accessible by removing the rear seat (you pull on 2 hooks and lift/pull the rear seat out to remove it)... there's an access door underneath.

 

its located in the tank. nissan says it does not have to be changed but like any filter it should be changed on whatever basis is warranted by the owner. several members have replaced theirs with favorable results with better MPG and better throttle response. i used to have a link on someone's how to but its missing for the moment. maybe someone else can toss it in here.