I took my res off when I first got my car cause it was rotted out. It sounded ok until I hit the higher RPM's, then it was RASP city. Now I have new pipe, ubend delete, res and 2 turbo mufflers with NOOOO RASP. Take these guys advice bro, they have been there done that and so have I. I regretted getting rid of the res about a day after having straight pipe welded in which cost me $68. My new exhaust was $300 and totally worth putting the res back on.