Brief loss of power on the highway (2001)

There is a recent development with our 2001 toyota prius (about 62K miles) that it will lose power while driving. It isn't that the engine dies, thank goodness, but rather that pressing on the peddle has no effect for a few seconds. In all three cases it has recovered back to normal driving expectations. Two of these incidents happened within the same minute just today.

In the past we have experienced periodic sluggish behavior going up hills (accompanied by a faint ticking noise in the engine), but these new incidents have been occuring on level stretches.

There are no engine warning lights on the dashboard. Because there are no lights, my local toyota dealer says there's nothing they could do. (This is what I've come to expect from them...either the onboard computer tells them something is wrong, or we get them to drive it and experience it for themselves. But with intermittent problems, the second option is usually a waste of everyone's time.)

Since our dealership won't help unless we can summon this up on demand, and they had "no idea what could cause it", I was wondering if anyone here might know possible causes? My concern is partly that it is simply unsafe on the highway when it occurs (what if it happened when merging?), but also that there is a greater problem that needs addressing.

As someone who knows very little about cars, my first thoughts were:

1) Poor quality gasoline. If there was water in the fuel, would that cause this sort of behavior?
2) there is a problem with the transmission being in the wrong place for the current speed

Any thoughts would be greatly appreciated. I'm so glad I've found this site in general.

 

That's a new one to me. I'll have to search these forums on this subject. I think we're going to try to put some gasline anti-freeze in the tank to get rid of water in case it is just water bubbles, but if that has no effect, I'm curious to know more about the sensor.

Thanks!