It will throw a shadow code to BMW when they hook your car up. Thats a no go for them. You can just look for the small vacuum cord that plugs into the muffler. Look under the drivers side rear wheel. Pull it some so there is a bunch of slack. Fold it in half, and zip tie it. Your hands will get a little dirty, but it takes 2 minutes. Plus if your car is still under BMW warranty all you have to do is cut the zip tie before you go in, and no one will know.
2007 BMW 335i with Premium Package, JB4, AFE DCI, RR OCC, Catless DPs, AFE Silver Bullet, and other cosmetic stuff.