I am very new to this car modifying stuff. I have an 95 Z28 and am going to do some mods. The first thing I am going to is add a cold air intake as that was a recommendation and made sense to me too. Also, I have a flowmaster exhaust that came on the car. Is this an upgrade (I thought it was) and is this considered a cat back system? Is it worth keeping (I've heard of flowmaster and thought it was good). Has it added horsepower to the stock car? If so about how much?