Exhaust tail pipe

I'm assuming you have twin pipes and one has a valve closing it off?

If it is anything like the one i had on my BMW then is is there to maintain back pressure on part throttle openings to aid the airflow out of the engine. If you floor it then the valve opens for more exhaust flow.

I could be wrong but my two cents.......
 
What is the valve on the tail pipe of my car and what does it do
Do you have any pictures of your exhaust? I'm assuming it's standard. Only my 3.2 has twin tailpipes but no valves that I can see. I assume mines still standard, they look like milltek tailpipes but have no logo on them.
 
What is the valve on the tail pipe of my car and what does it do

It's vacuum operated and controls the noise. The flap is shut below around 3500rpm and then opens when the revs rise to give the burble sound. It's on the R32 also, and is a popular mod to blank the vac pipe to keep the flap open to give the noise at lower revs...