Please Help! 720 stalls out...

[DatRat66]

Everything was going fine and then all the sudden my truck runs like crap.
thinking it was a simple fuel filter change, i got a new one and it did nothing. i changed the 02sensor and it seemed have fixed it. then i drive around and my engine cuts off. i start my truck back up and start driving and the fuel pump starts whining like crazy. it goes back to normal and truck stalls out. it does this repetedly. runs fine-fuel pump goes crazy- then stall.
i changed the fuel pump for a new oe replacement and still the same thing.
my 720 has had the carb swaped for fuel injection.
what is going on. please help me, ive been at this for a week.
could it be the coolant temp sensor? cause i noticed my gauge isnt reading anymore.
could it be the coil packs?
ive done a fuel tune up. plugs, wires, starter motor, fuel pump, cap and rotor, all lubes and filters replaced!!

[tanman]

Just had this happen to me it was my egr sticking. Could also be a vacuum line

[NoNewbie]

If you swapped out to fuel injection there is such a thing called a wax pellet in the fuel injected carbs that eventually gives you what seems like major problems but is actually simple to fix. Go to your neighborhood Nissan dealer and ask to talk to a mechanic or parts department, I would hope they would be kind enough to explain it all to you.