It's been a while since I had my 04 f150.. Well since 2011 when I got my superduty and I've been out of the gasoline game. On that truck I can't remember what two hi flows I replaced my stock 4 cats with. My brother has an 06 with two larger cats and he has the roush o/r kit also and wants it louder. I said to look into smaller hi flow cats and that'll make it louder. Without throwing any codes what cats do you guys recommend without breaking the bank?

 

Wow apparently it's been a LONG time since I was on here.. My profile sig is ancient lol