ATTN:!! Everyone who has a problem with a hesitation at 3500 to 4500 rpm. I have solved the problem that can be causing this hesitation.I have read many solutions that can resolve this problem and none of it worked...I should know cause I have spent numerous hours trying to figure it out and wasting my money on MAF,Throtle body's,fuel pump,sensors,and many more parts for the car and never fixed it.Finally I had enough of buying and reading possibilities that can fix the vehicle.So i took it upon myself to see what my warranty for the ECM was for this vehicle and it is 7 years 70k..So today i took it to Nissan and had them replace the ECM...and Surprise the car is running beautifully.!!!NO MORE HESITATION!!!! :

To bad it took me this long to figure it out and a whole load of money!!!So Please if you have this problem with your vehicle please consult with Nissan first on this issue before spending money on this problem and resolving your issue...Trust me it took a whole lot of convincing Nissan to replace my ECM, But it is your right to receive what you want done to your car under the manufacturers warranty.
Thank you for reading and i hope this is useful for you in future problems...