My wife drives a 2010 Aveo5 LT. She said about a year ago that the car was making noise on acceleration, which I am sure now is the flex portion of the exhaust pipe being bad. Recently she was driving back from taking our dog for a hike when the car just slowed down and she pulled over because regardless of how much gas she gave it the rpm's went down. I did oil and plugs, topped off the coolant. It seemed to run better for me but she is concerned because she says the transmission slips sometimes and stutters other times. I have checked the fluid and it looks good, smells and tastes good too. I have new fluid and filter to change it out once the weather warms up, just has not yet. Any help, even pointing in the right direction, is appreciated. The car has about 62,000 miles on it, don't know the last time the fluid was replaced, to be honest.