Diesel or petrol engine?
is the service engine light on?
how does the vehicle Rev in park? can you rev the RPM's up no problem?
Thanks, XXXXX XXXXX as you have no problems building RPM's in neutral then we can usually rule out any airflow sensor issues,
Your more than liekly looking at a fueling issue, whether related to the pump or more coomonly the suction valve on the side of the pump.
You may want just make sure your you don't have a clogged catalyst also. Although fairly uncommon on these trucks, it can be known for similar symptoms.
Unfortunately, I am not familiar with your area.
While you don't neccessarily need a Nissan dealer for a reapir like this, do get someone that uses up to date diagnostic equipment so if they need to calibrate the
SCV or something they can do so fairly easy.
Sorry i am not familiar with your area though, or I would have been happy to help.