if you install a powervault and still have a stock exhaust tip, it greatly helps by getting rid of it for one that does not megaphone the sound.... hard to say.. but I changed out my exuast tip and it is WAY better on the sound now...but is still too loud.

Bottom line for all of you out there who enjoy the quietness of the stock muffler, if your like the quiet ...the powervault is NOT for you