[Troyota]

You are probably talking about the "Y-pipe" it's the pipe that connects the two turbos to the rest of the exhaust. A lot of people do replace this piece, but if you do, you will probably need to get a Y-pipe/Downpipe combo since the new Y-pipe will not have the same bends and connection point as the factory downpipe. I'm not going to replace mine...I've already got a Tanabe downpipe that mates to the factory Y-pipe.