Regular CAT Converter VS. High Flow CAT. Is there a difference when it comes to smog?

[s13rookie]

Originally Posted by SexPanda

Go to autozone and pic up an OEM one. A high flow cat is high flow because it doesnt filter as well.

I must disaggree. An aftermarket air filter filters better and flows better than a stock one. I think materials and design have a lot to do with it

Also, I remember seeing a dyno a few years ago of a high flow cat versus a gutted cat. The high flow won by a couple hp, im not sure if it had to do with too little backpressure, or possibly turbulence