2009 softail rocker c . I put on a k&n air filter but kept the stock air cover. I hear it sucking air when I ride. Is this normal? I have Vance and Hines exhaust 2x2 . I just don't remember it sucking this much air when I first got the bike, now I'm getting used to the pipe noise and can hear it. Intake is super clean, bike runs great! It's a beast! Gurgles like an old 60s drag car on the line.

 

That's the stock A/C cover that makes that sucking noise. It needs to be changed to match the bike's attitude. Listen to your bike!