I know the Stillen exhaust it quite loud (argueable) with a Y-pipe. The best performance exhaust while mantaining a fairly quite ride (not as quiet at stock) if the
Hong
Kong
Sports muffler (
www.HKSUSA.com). However, for the quietest ride while still mantaining a good performance level will be a 5th generation Maxima exhaust. Lots of people tend to go with this, because you can get them used quite easily, and they are not much louder than stock. Whatever you get, it will always be a little louder than stock because of you're y-pipe. Just trying to help

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