I got my new exhaust last week and my car kind of shakes at idle and last night I hit about 100 and it sort of vibrates. One of my friends told me that sometimes straigh through exhausts tend to shake sometimes. Could this be true? It didnt shake before when I had the exhaust coming straight out the cats, but I added about 3 Feet on each side with one bend so they come out the side. And it started haking a little the same day I got my pipes put on.