[Opie550i]

So I'm now on my second set of the Active Autowerke Signature exhaust. Both of them had this same whistle sound as soon as I get the car up to about 4000 rpm. Does anyone know what could be causing this?

Here is a link to a video the shop took when trying to diagnose the problem.
https://youtu.be/1Pn0HJdUpiw

[AMT92]

I have the same issue with my M5 mufflers. Exhaust shop said they could re-do the piping but it may very well be the muffler itself. I've just learned to live with it for now.

[mike@x-ph.com]

Check with AA

[ey2001]

Would a muffler make that noise?

[Opie550i]

Originally Posted by mike@x-ph.com

Check with AA

Been working with AA for a few weeks on this now. They sent a second exhaust to see if it would fix the problem. It didn't.
On Monday the shop that did the install spent the day trying things to fix it. Determined it is only the left exhaust that is making the sound and if the exhaust is removed from the left side the whistle goes away.

Apparently I received the last 2 systems from AA's build so there are no more units available. Waiting to hear back from AA on what options are available now.