I bought the KN kit for my 09 a4. On all of the viedos it sounded great and couldnt wait to install it. After install I was really disappointed. When shifting gears it sounds great releaseing the pressure similar sound to a bov. But when reving up to and after 2500 it sounds like a high pitch whistling/squeeling. It sounds likes belts are loose. It's drawing attention for the wrong reason in my opinion. Another downfall is I was expecting simliar or better gas mileage and I am getting about 2 less mpg. Does anyone have any input on this? Is anyone running this kit and have similar or different issues. Please let me know. I may be taking off soon to try and sell. I only had it on for less than 2 weeks now.

SOMEONE PELASE HELP OR GIVE SOME ADVICE

 

I had the same issue with my K&N intake. What you are describing says it all. I contacted K&N about buying it back from me, and without hesitation, they did. I would purchase products from them in the future because of their willingness to stand behind their products 100%. I was very impressed.
Back to your issue though; since removing the K&N intake and installing the factory air box again, I have noticed that the 'squeal' is still there, however, less noticeable. I have come to realize that the K&N intake only amplified a sound that was already there.
As for what is causing this sound, I'm not quite sure, but I'm suspecting a pin hole in the diaphragm of the diverter valve. I just haven't had time to take it apart to look just yet.

 

Thanks for responding. How about did you go returning it to k&n? I still have the reciept and all original boxes. How did they reimburse you and what amount?

 

I contacted them via email and told them of my disappointment in their product. I asked if they would buy it back from me, and they responded telling me that they have a 'satisfaction guarantee' commitment, and that if I was unhappy with the product, that they would buy it back from me. They asked for all of my information (name, address etc), and a copy of my bill of sale. I sent it to them; they sent me an RA# via email and told me to ship it to them in California and then they'd issue me a check for the full purchase amount. I sent it to them, and within about 2 weeks, I had a check. Good luck!

 

Thanks alot for your help. I contacted K&N and you were right. They stood behind their products 100%. I have had their products in the past and it's great quality. This product just wasn't working for me.

 

I agree completely. As upset as I was that this product wasn't working for me; I was very happy in the end that K&N stood behind it 100%.

You're very welcome for the help.