Get an exhaust shop to weld in a vibrant ultraquiet resonator it should help a good amount, but it wont completely fix the problem. If you want anything close to stock sound levels you need to get a different exhaust (invidia Q300 or similar), add a muffler (that's not N1 style), or go back to stock setup. Cheapest option is to add the resonator and see if its tolerable then.
Adding a cat to the downpipe (or replacing w/ catted DP) would also help some, but that would require a tune to make sure the car is running at max efficiency w/ the increase exhaust restriction from the cat.
Adding a cat to the downpipe (or replacing w/ catted DP) would also help some, but that would require a tune to make sure the car is running at max efficiency w/ the increase exhaust restriction from the cat.
