Nissan Expert Needed

I am working on a 2002 Nissan Xterra 3.3L 6 cyl.   Kept cutting off.  Replaced a bad fuel  pump.  Ran for about 2 weeks. Starting cutting off again.   Have to wait 2-5 mins before you can start again.  Replaced fuel pump again, fuel filter and fuel relay.  Continues to cut off after only a few minutes, and wait again.  I am thinking computer (which there are 2 as you know). Can get expensive to customer. Any thoughts