I just got done installing a K&N FIPK Gen 2 cold air intake and I just want to make sure what I'm hearing is normal. I know I'm going to hear air being sucked in and that sounds pretty nice but when I let off the gas is when I hear this loud whining sort of sound as the rpms are dropping. I even tried it with the cone filter off and it's definately coming from the air intake. All clamps are tight. Do I have to give it some time to adjust to the increased air flow or what? I had the battery disconnected while I installed it so it should have reset itself.

The sound should go from a growl when on the gas to a low sucking sound as the revs drop. It's not really the sound you would expect (like a whistling) so what you are describing sounds right.

It seems a lot of us get that sound after installing the k&n. There was someone on here who had a post of installing one who had the same problem. Their remedy was to drill out one of the lines that feed into the body of the intake tube to make it the same size of the k&n's hole. Do a search to see, it was quite a bit ago so my accuracy might be off a bit.

do a search for -drilled out the k&n fipk- here is where you will find what i mentioned. good luck

Thanks for the info. I found the thread you were talking about. I'll have to think about whether I want to alter the line size. I would think K&N would have the opening size engineered to the correct size, but maybe not.

Might be worth your time...I took a round file and widened up the holes in the plugs on the sides of the intake, and the hissing sound diminished a little bit, so hopefully everything is getting more air. Good luck!

Well I took all your advice and decided to open up the two lines and it worked. The whining/hissing sound is gone and all I hear now is the growl. I had a hard time believing that K&N had the holes too narrow but when I took it apart and looked at the opening size after it tapered down, it was way smaller than the factory opening so it made sense to open it up. Thanks for the good advice guys!

Yeah, that was a manufacturing defect in some of the kits. Glad it's all fixed up!