i would agree...sounds exactly like a miss or detonation which are both somewhat common. Do what hot said and then come back if problem persists...9 times out of 10 it is the plugs.1) Spark Plugs(start .032 and go lower)
2) Coil Pack Connectors
3) Coil Packs
Thats how I would do it in that particular order....start with the cheapest and work your way towards the more expensive.