I daughter recently drove to Las Vegas in her 2006 Tucson, while driving up a steep grade vehicle started to sputter and finally came to a stop and engine light came on. After approximately 5 minutes the vehiclewas restarted and was able to coax the vehicle to a gas station where they reset the warning light and told her it was probably bad gas or water in the tank. They refilled the tank with premium and drove to Las Vegas. On the way back she notice that the vehcile would sputter lightlywhen going up any slight grade. Any ideas on what may be causing this?

 

If the warning light was the Check Engine Light then you need to find out what the code was. Why did the "mechanic" clear the light without getting the code? The code tells you what the problem is. I'd suggest going to a real mechanic.