how would i make it custom and still be able to pass inspection

 

Dontgo throughinspections?

 

i dont know how inspection work, but maybe try a purple horny muffler

 

screw the muffler and run a 3" exhaust pipe all the way back and see what happens[8D] then come time for inspections put the old stuff back on lol, I'm probably going to bypass my cat converter, and get the vibrant cat-back Dual exhaust, and Pacesetter headers.

 

Won't help you enough to notice it.

 

sound or performance wise?

 

Performance.

 

Seems like it would do something for performance, cats filter the air so its no so the exhaust isn't so polluted and bad for the environment or whatever, so if its filtering the airflow that would restrict it, thats just what i heard im probably way off.

 

The cat converter on our neon isn't restrictive enough to show a gain when removed.

 

you may show a power lose