i have a flowmaster american thunder exhaust system with the original 40 series mufflers. do the cats make a big difference in sound? i have a stock H-pipe with 4 cats, i am getting an off road pipe soon, will my car be alot louder? my car is some what loud but not loud enough for me. thanks
Yes no cats will give it that very loud and distinct mustang with flowmasters sound. Just make sure there are no emissions tests in your area or that will kill you unless you change it out for the stock pipe for the test.
Putting my O/R x-pipe on changed my exhaust note more noticably than my catback. It got ALOT louder. I also have a much different exhaust combo than youl, so your results may be different.