is it a catback alone or do u also have the downpipes??
You do not have to install downpipes although they will give you more power, better flow, and a better sound than just the catback alone. Some people resort to "piggy pipes" which are where you remove the honeycomb structure out of the stock downpipes at a lesser cost than aftermarket downpipes. On my particular S4, I have opted for aftermarket downpipes, and a gutted stock exhaust. Please visit my page and see if you like the sound.
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