While installing a second exhaust line is just a fleeting thought, there are a couple questions I have out of curiosity.

1. Is it advantageous to have a split system from the cat back over stock?

2. Would the second line need its own resonator too?

3. Also, does my car (03 TJ exec) run the 2.5" or was that only vr-x and sports?

Cheers!

1. no
2.no
3.your car should have the same pipes as the sports only difference being the rear muffler

Makes it louder and look different.