I just installed the K&N 77 keeping in mind potential air leaks that could lead to a whistling sound. I just test drove it and it has a definite Growl but not a whistle.
organcory, if you are hearing a high pitched whistle I think you may have an air leak in one of the connections from the throttle body to the filter. I suggest you go back and check each connection on both sides of the rubber tube and make sure the clamp is located over a solid foundation.
Again, just my .02c but I don't think you should hear any whistling, ie high pitch sound.
Oh yeah, btw, a cold Beer is in order for K & N, this thing looks as cool as sh#t!
