New member here and this is my first post. I have had a black BMW X5 4.8is for the last year and did my first mod to it today. I removed the resonator and replaced it with 2 staight pipes just like others have said to do. I got it back and love the sound... It is amazing watching the heads turn when I go by. The only problem is that I feel like I may have lost some power. It might just be in my head, but I would like to know what others think. Thanks and look forward to hearing everyones input