I'm finally going to pull my engine and replace the leaking rear main and do some other stuff. Since I'm getting the pcm redone and deleting the emissions, I'm going to go ahead and cut off the CATs to make pulling the engine easier. I need to know what size pipe is before the CATs so I can get an adapter to put on 2 1/2" exhaust with an x-pipe and flowmaster 40 series mufflers. Eventually I plan on getting headers, but for now, this will have to do.