I found a little something, may help. not sure.
http://forum.e46fanatics.com/showthread.php?t=611798
Source:
http://forum.e46fanatics.com/showthread.php?t=611798
Source:Yes! If the orange seal goes bad you will get a really bad vacuum leak. You will have mixture faults for running too lean and the car will run very rough at idle to the point where it will be misfiring. If you keep driving like this the misfire faults will cause the DME to shut down a cylinder.