One problem related to check engine light on has been reported for the 2007 Toyota Prius.
Master warning light came on along with vehicle stability control, brake & check engine lights. Took it to my Toyota dealer (rice Toyota, greensboro, nc). I work 79 miles from home. I called my Toyota dealer, a service rep said it was ok to drive as long as the warning lights weren't flashing. Diagnostic codes indicated the hybrid converter/inverter was bad, they cleared warning lights, which stayed off. They said it may have been a "glitch", if warning lights returned, bring it back. They returned on 3/1/13 while driving to work. I lost power while on I-540, pulled over onto shoulder, turned off engine, restarted it, got back onto I-540 & exited at nearest exit. Lost power again. Pulled over, went thru stop/start process, drove 3 miles to work. Drove home with warning lights but no power losses. Took it to rice Toyota next morning. This occurred barely 2 weeks after the 100,000 mile powertrain warranty expired, galling to say the least, as this part "is" the hybrid system per the service rep. Have you received other complaints about this component?.