Duel Exhaust

can't spell thanks for catching that rascal

I think I've seen a warning from Ford on the 6.7L not to alter the exhaust system since the whole system is tuned to a certain pressure. They warn you to keep those vents near the tail end on the pipe open too.

I had one on my truck. Loved it. It was quite loud when towing though. Last year we went to Florida for our yearly trip and the loud exhaust kept my 16 month old daughter awake the entire drive. When we got home I took it off and put the stock exhaust back on.

Modern engines are very well designed as they leave the dealer. I doubt you will recognize much gain in power by adding an exhaust and may actually lose some low end power.

The main reason to change exhaust is for sound and looks. That's why I did it. I miss my exhaust when I am not towing... it wasn't worth keeping my daughter awake on longer trips though.

Legally he can only do it after the cat and it wont make much difference other than sound. (assuming you mean "Dual" ex.)