If you hear a lot a lot loud noise and not just a little more noise you need to relocate the CAI filter. The louder the CAI is the more hot air your taking in. The quieter your CAI is the more cool air your taking in resulting in more power and gas saving.
I also have the k&n. Bought one because it was on sale at Cold Air Intakes|4WheelOnline. This intake is less restrictive and really loud. Didn't notice any mpg gain but throttle response is a lot better now.