Just installed my AEM CAI and man do I love it. My engine can breath now. It's like putting a breath right strip on your car. I love the note from it at about 4200 RPMS. But before I installed it I noticed a high pitched whistling noise that would disappear around 3k rpms, but now it is even more obvious and still disappears around 3k rpms.But it does it from idle to 3k. Does anyone know what it might be. It's not the intake cause it was doing it long before I put it on.