My bud also wants to put on a racing beat header, and he is wondering if a prescliencer is the same thing as a high flow cat or do you have to have both?

 

A presilencer is most definetly not a high flow cat. all it does it make your noise coming out a little quieter. A high flow cat can still be emissions legal and a presilencer isn't. but you can tell your parents that they're the same thing so you don't get in trouble when you get presilencers for more HP compared to a high flow cat.