Ok, I have an SLP Y pipe and hooker catback. It's 3 inch y pipe, 3 inch catback, but I still have the stock(possibly original) cat... that's like 2 1/4 inch I think. Does anyone know if there will be a difference in sound when I get a 3 inch highflow cat? Also, is there any difference in the catco high flow versus the dynomax superconvertor besides money? And my exhaust has this really gasy kinda smell right now... is my cat shot or does it just smell like that? If its on and I stand around it my clothes are soaked with that smell... Thanks.

 

Going from a stock cat to a hi flo one will help the sound out some, nothing like putting a cat-back or headers on, but the increased flo of the cat will help sound.

 

There is a big difference from having a stock cat and getting a hi-flo cat sound wise. My friend had a cutout on his car with the stock cat and it was loud but when he got a hi-flo one the car was so much more louder.