HI
a DIY'ers choice is to change the whole Y pipe. I've attached a link to Wiswinds photos from when he did the job. I believe others have too. The main problems are lack of work space and old rusted, cooked on fasteners. As to where to buy, I'd look at rockauto.com.
Good luck
http://rides.webshots.com/photo/1291...11220610mzvEni