I took my 2000 GT for inspection and it didn't pass because I didn't have any catalytic converters on it. The garage put some stock ones on to pass and they made my car sound like crap. Before them my car sounded great, but now it got a lot quieter and my exhaust only makes a sound when accelerating. I have a MAC catback, MAC long tube headers, and a MAC scavenger pipe. I am looking into getting a new H pipe with cats or just new high flow cats. I was looking at the Pypes high flow cats but I am not sure yet. What do you guys think is the best high flow cats to make my mustang growl again?