something keeps cutting on and off every few seconds?

It would help to know why you think something is "cutting on and off every few seconds," and what that something is. It could be that most hybrids will alternate between running the gas engine for a while, then stopping it to run on battery only. "Every few seconds" sounds a little fast for this, but I've never driven a Prius. This improves efficiency since, in the case of a 3rd generation Prius, the engine alone is about 30% efficient at 15 horsepower, but 40% at 30 horsepower. Since it only needs about 15 HP to cruise on the highway, it saves gas by alternating between 30 HP and 0 HP (off).