Originally Posted by AW750Li
what did bmw say when you brought the car in with the x pipe? I might be interested
The dealership didnt seem to care at all. I even had an O2 sensor replaced under warranty and nothing was said about the X-Pipe. Some dealerships may say something, but I dont think you'll have a problem as the primary cats and O2 sensors are still there. You can also have your stock X-Pipe welded back in, in case you have to go back to stock.
When my lease was up I had my stock pipe welded back in and was not charged for anything. According to my client advisor, the car was CPO'd and sold a month later.