hesitation

I own a 2000 with the 2.3 miller cycle engine. it hesitates at full throttle and runs fine at half throttle. does anyone know what the problem is and possibly how to fix it? thanks for any input

            check your MAF sensor, my friend's 2000 maxima  was doing the same thing, he change the fuel filter, didn't help, i replace the MAF, that took care of the problem.