Tweaking my Tubi

I have the same set up and had the same problem. You need to loosen ALL the clamps again, the headers, cats, "Y" pipe, and bypass valve. Wedge a small piece of wood at the tail pipes to overcompensate them to the left a little, and start retightining each clamp 50%-than 75%- than full. It was a pain in the ass, I had to do it 3 times to get it right.

 

I have a race tubi and the tips are very large and totally fill the bumper exhaust openings.
Unfortunately both tips were not aligned and no amount of adjustment of the stock cats/muffler would line up both tips at the same time. The main problem is the stock clamps at the cat/muffler connection.
If this were a flex joint there would be less of a problem (but it is not). Tubi's are hand made and this allows for some tolerance in the manufacturing process as well. I decided to modify the exhaust.
What I did was cut off both tips and reweld a 2 bolt flange both to the muffler pipe and the tip pipe.
Now you can bolt each tip on seperately and adjust them individually to get a better fit. The flange is behind the bumper and not visible.
An added bonus is now the muffler can be removed and re-installed without removing the bumper......I guess it might be possible to replace the clutch without a bumper removal but I've not done this so far so I can't say for sure.