as long as your not throwing a code, your fine. They just hook the obd up and walla, your done. I went in with my 2000 z28 with long tube headers, off road y-pipe, and very loud slp "loudmouth" exhaust.!!!! I think as long as theres no cel showing on your dash then your fine.

 

+1

Do a smog test with all the parts first and see how far off you are.

4G63 motors are actually pretty efficient, you will be surprised how close you just might be before you reinstall the catalytic converter.

 

This is a prime example of why I hate the government. they should have 2 lines, one for high performance cars that cant pass but deserve to, and civics with 390,000 and 14 exhaust leaks

 

as long as you don't have a cel on you should pass if they just do a computer check. if they do a visual or sniffer test you will fail.

is your cel on?