Originally Posted by shortseller
Are you 100% sure it works on all non 335IS models?
I only ask because when I called my local BMW parts shop to ask about purchasing the 'IS muffler for my 2010 335i coupe they told me the exhaust flap system worked differently on 'IS models and thus it would not work correctly on my model.
So it worked correctly for you?
I believe the IS and PE both do not use the exhaust flap in the left side pipe so the vacuum tube just needs to be plugged. On the PE there is a spot to connect and plug the tube, so the IS exhaust should have something as well. The exhaust flap is not necessary anyway, and most users here have done the "golf tee mod" which is a pretty noticeable and free mod.