I recently decided to go for a custom exhaust since most of the catback system out in the market are not compatible with FWD cvt. now I am order stainless steel tubing for the pipe, what thickness should i go for, anyone got any ideas? thank you for your input!

 

3" from the cat and 2.5" from the y pipe/resonator.

 

What mufflers are you using? You probably want to your piping to match up. Are you getting a HFC or test pipe? You probably want the piping to match up there, too.