Nissan Titan Performance?

I have purchased my second Nissan titan which is a 2005, before i had a 2004 both automatic. My question is that the 2004 had great response through all the bands when i pressed the gas pedal in each gear and was quite fast and it was all stock as far as i know. As for the 2005 it isn't as responsive and quite sluggish, not as touchy in the gas pedal and i think i need to get it tuned or something along those lines so i am looking for some advice