Ok, I just got a full tune up, including wires, plugs, flush, filter, pv, the whole nine yards. The hesistations went away, but a week later its back. It feels like it pauses slightly when I'm reving in the higher rpm's about to switch gears, especially in 1st, 2nd, and thrid. I use mid grade gas, and I don't have any mods besides a CAI. What could it be? My battery is weak, and I read about how a battery can acause a hesitation in higher rpms, so I going to replace it and see what happens. Only other thing I can think of is the coils. No check engine light is coming on. Does any1 have any idea of what it could be?