high pitched whistle sound? from exhaust

KB2

So, my exhaust lately has been making a high pitched/whistle type of noise lately upon acceleration, and it's quite honestly driving me nuts.

I have the hks hi-power, and it was great, until I recently got ppe long tube headers installed. And while I now make alot more power and the car feels great,it dosent sound great....

So In an attempt to experiment, I even removed the hks and installed my tanabe system. Now this one doesn't whistle, but it feels congested and is very raspy. Before headers, tanabe sounded great!

So now I'm in a debate, with a y pipe the car feels slow and you can tell a difference,but the whistle went away. With the "h pipe" it feels great, but whistles....

now the hks h-pipe section is not welded together, you bolt it together, so maybe that creates a whistle? Compared to a traditional h pipe?

My question is, how do I get maximum flow for my car, with my new headers, while still making it sound fantastic?

I'm considering the aam s-line mid pipe section. With tanabe axle-back....


If anyone has some feedback, I would love it. Because I'm going nuts over exhaust