I'm trying to find the right muffler to put on my g6, does anybody know the exact measurements for a 2006 gtp sedan? I'm having trouble finding one and I'm not sure of the right dimensions for the inlet and outlets and what not. Any help would me MUCH appreciated! thanks guys.

Try a search....tons of info on this.
Your stock pipe is 2-1/4". You want a single in and a dual out (easiest).

Most bump theirs up to 2.5". The best sized tips for our back valance
is 4".

Also you will need the dual out back valance from the GTP. I posted the part number the other day.

Time to get your feet wet with the search button. but hollar if you have any problems and Ill help.

I have a GTP, so I'm already good with the back valance. The mufflers are a little different with the gtps because of the dual exhaust. I've see the mufflers with the single in dual out but the problem is the 'in' has to be the same size as the 'out' i believe. I need a muffler with 2 on 1 side, 1 on the other, offset (not centered like most), but all the same size.