hi I have a is250 and ever since I installed the tananbe medallion exhaust. I got it cause it was supposed to be the quiet ones. But it drones and mumbles so much inside the cabin at low rpm or cruising. Its much louder in the cabin than outside. I was wondering if there is anything I can do to it?
Probably reinstall it? Maybe something got messed up during installation?
welding something like a resonator on the side of it?

What could be the problem and what what could I do to fix it. I am aware that automatic transmissions and low rpm drone is pretty common but I want to try to fix this before having to replace it with another one.

 

Mine does the same. Checked install and threw some Second Skin Damplifier Pro on the trunk floor. Helped some, but I think I'm just used to it now.