How do you buy a Z without seeing the mods? Get rid of the CAI and get an 06 airbox with a K&N drop in...gives the most power(Even if it is only like 3 hp haha) It may have diff gears like the 3.8's or something and that may be what you are feeling but I doubt it. Actually if you are new to the Z, you just may not be used to it yet...it likes to slip the tires stock.

Will_Evo