so i was thinking that the race header elimnates the cat. so if i were to gut the cat out wouldn't it be the same and i will still be able to pass emissions cuz it looks like the cat is there??? so the question is.... is there really a difference between racer header and gutting it out???

 

If you gut your cat you won't pass emissions. And headers usually have larger diameter piping as well as providing smoother airflow allowing exhaust air to pass thorugh easier.

 

yea but u wont be abke to tell if the cat has been gutted or not. and i mean how much smoother.... like so much smoother to spend 400 bucks???

 

You will fail if they hook up the sniffer on the exhaust although some states they don't require that so check local laws. A better way to explain it is the difference is the same as the difference between a new cat back versus stock exhaust.