NEED HELP!!!

I have a problem and was wondering if any one else has had this same problem, when i come to a stop and give it gas the motor cuts out, and suddenly picks back up. The people at the dealership, says nothing is wrong with the car, they state that the last time that it happened they wiggled the spark plug and it was loose. PLEASE HELP ME find out what is wrong with my car.

 

Isn't your car under warranty? Don't waste your money/time fixing problems like that yourself.. go to the garage & take one of the mechanics with you on a drive if that will help show them what you're talking aboiut