Noise?

Got a 2004 6.0 and at idle it doesn't have as much of diesel sound as my dads 05. It has more of a rumble I'd guess you'd say. Also in the driver side fender well it sounds like air I'm guess this is my k&n intake. The passenger side sounds fine. Didn't know if ford changed pilot injections between years or if something wrong?

Sent from AutoGuide.com Free App