| Unless you know you definitely have a bad oil separator (perhaps complete with Chewbacca noises), you may simply have the commonly broken lower oil separator vent hose. You can see the broken hose rather easily with a light by just taking off the air filter box and the MAF and looking under the front side of the electrical junction box under the intake manifold. It's a $10 part and easy to remove and replace by hand; no tools needed. Just reach in and replace it. Some pictures to help you look in the right spot can be found here:
It just might save you a lot of time and trouble. It worked for me and got rid of a slew of codes all at once including my rough idle and SES light.
Last edited by gsbmw; 06-23-2010 at 05:50 AM.