Super Exhaust leak!!

[powerstroke welding rig]

Last week I built a new Y-pipe. I cut the old bellows out and tig welded in new heavy duty exhaust flex hose. Very similar to the Maryland Diesel performance Y pipe. Yesterday while I was installing the Y-pipe I removed the turbo and took apart and cleaned it up. I followed the instructions too a tee. Everything went back together very well. There was absolutely no problems. I reinstalled the upgraded Y-pipe and turbo. Everything seemed too line up good. Tonight when I started the truck I have a severe leak coming from where the Y-pipe meets the turbo. I mean its really given' er out of that joint. Now besides the obvious (the connection is no good) is there a possibility that I got the V-Band clamps mixed up? The exhaust clamp put on the Y-pipe spot and vise-versa. Are the clamps different sizes?? My other thought is that I so badly butchered my turbo cleaning that the exhaust hits the turbo and has no where to go and just starts chugging out the Y-pipe/ turbo connection??I started tearing back into the truck again and tomorrow I will attempt to fix the problem but I thought if anyone had any ideas that would be great. I have no code reader so please don't ask what codes are coming up.

Thank you very much.