Matt Daniels

I worked as a service advisor in a shop most of last year and we had a customer with a high-performance Mustang with a custom exhaust on it.

What they had done, was create a y-pipe just before the cat. One end of the Y went to the cat, the other was open but could be capped off. So, for racing they would just uncap the one end and have a straight exhaust, then they would cap it back off for regular driving.

Of course, who knows if this would work with a more modern engine/electronics or if it could even fit under a TT.

Just a thought.