Hi, first of all thanks for taking your time and reading this. TOday i had a shop install my Berk's Hfc which is running stock oem exhaust . After the installion was done i went to rev it up i hear this hissing sound coming from below, anyone might know what the problem is? here is the link to the video sorry its dark so you cant see anything..

 

That noise is normal. I had the exact same noise on mine with three different exhaust configurations:

resonated test pipes and stock exhaust
resonated test pipes and an EVO2
Crawford high flow cats and an EVO2

It was worst with the test pipes and the EVO2. Some call it "rasp". Personally I hated the noise. Not a problem for me anymore since I went turbo...

 

that whistling doesn't sound like rasp, but idk what it is

 

hmm weird i watched some of the others youtube video after cats being install you dont really hear that noise...but yea after i install my hfc i jack it back up to see if there was any leaks and NOpe i guess that noise is just bothering me..

 

That normal. It's louder with test pipes. I almost eliminated mine using a Magnaflow resonated x-pipe.

 

i take you guys words for it, just makes me less worry and that i can sleep good tonight :P thanks for the help to all of you