There is an odd noise coming from my air filter, it sounds like a hissing sound, Its a new truck to me so I'm not super familiar with it as I was with my last one. Any idea on what it could be? Leak in the intake system? Thanks for your help!

 

Make sure the lid is on good. If it is, then it is normal.

 

There is also a vacuum hose on the back side of the air hat just to the side of the throttle body. If it has been removed there is a chance someone forgot to put it back on.

Also make sure its sitting correctly and check to make sure the gasket between the throttle body and air hat is still there and in good condition.