When I start my truck up, it doesn't matter if it is a cold start or after its been running for a while...it revs rather high (1500 rpm range) and the K&N hisses EXTREMELY loudly. Any ideas as to why this is? I don't remember it doing it when I first put on the CAI and it didn't happen with my last truck with the CAI...any ideas? Thanks in advance.

Ethan

 

Vaccum leak? Check all the vaccum lines for cracks...

 

It is not a vacuum leak, the sound is coming directly from the filter. It is extremely loud, it calms down after about 1-2 minutes. Just didn't know if this was normal or not. I don't remember it doing it when I put it on, or on my last truck, or on either of my dad's cars...