Center Muffler???

[Ericster]

just wondering because i havent seen this before but is it neccasary and if so whats it for?

[zbane]

For what year/model are you asking about? Perhaps you are referring to the catalytic converter?
Some more information will help quite a lot.

[Arne]

Well, if you are talking about the '71 240Z that's listed in your profile, the center muffler is exactly that - a center muffler. Nissan used two small mufflers to quiet the exhaust from the factory. This approach was quite common among import cars back then.