Originally Posted by pbonsalb
Yes, any exhaust except BMW's exhaust risks voiding the warranty. You are screwing with the AF mixture, making the car run rich at times, engaging in an illegal act, causing the engine to make more power than BMW warranted it for the average irresponsible owner to have, and so forth. Some dealers will make a note in your history log and others won't care. If you do have a claim, you can fight a denial if you can prove your mod had nothing to do with the failure. I would take it off if going in to the dealer. I would also run it with a tune so it runs right, and I would reflash the car to stock before going to the dealer.
Lol...well I guess I just stick to an axle back exhaust.