Unknown part on exhaust
 

Any one know what this is fitted to my exhaust? Guy who I got the car off said there use to be a wire coming off it but he didn't know what it did. Got a feeling it's something to change tho noise of the car???

http://i280.photobucket.com/albums/k...ds/image_1.jpg

Yip will be a valve to dull the noise down or increase noise, probably stuck shut lowering power lol