[Libloather]

It's not called a "mid muffler". it's called a "catalytic converter". it is a pollution control device, not a muffler.

Nope. I've got a catalytic converter and two mufflers. That's why one is called a mid-muffler. Learn something new every day - eh?

[Nathan Zachary]

Then it’s called a resonator. Yep you do learn something new every day, don’t you?

[Nathan Zachary]

To add to your educational experience:

Depending on the engine/exhaust, the car may have a resonant frequency that's kinda displeasing to most drivers. The factory will put a resonator in to kill or change this, so the resonant frequency is either much higher in the rpm/speed band and gets masked by other noise, or disappears completely. It's not a muffler, just a change in the exhaust shape to kill any reinforcement sound waves may get at some speed. W/o one, the car may be noticeably louder at some speed/rpm.