Yesterday my 2004 Prius started sputtering and had a slight stall when I accelerated from a stop. It happend about three times within three miles. I would push on the accelerator to go, and there was a hesitation, and a slight jerkiness once the engine engaged. After I got going there was a decrease in power for a few minutes. There were two pips on the gas meter when this happened, so wasn't out of gas. As I got closer to home the problem cleared up. Any idea what would have caused the problem? It seems to run fine now.