Originally Posted by RCZ

remember guys that metal contracts when it gets cold. If you have any sections with a slight leak, you will hear it most in the AM when you first start the car then it will close up as it heats up and expands. This change in temperature of the exhaust tubes are most likely the reason for the rasp you hear until the car warms up...who knows, maybe its a resonance point of the engine that becomes more apparent once we free up the exhaust?