****** IMPORTANT INFORMATION ABOUT THE REMOVAL OF THE INTAKE MANIFOLD ******
The German Auto Solutions CCV System can be installed with or without removing the intake manifold. This DIY guide provides instructions on installing the CCV System without the removal of the intake manifold. If you prefer to remove the intake manifold you will need to consult a shop manual or one of the many internet forums threads covering OEM CCV replacement.
There are two advantages to removing the intake manifold to physically remove the OEM CCV, neither of which I think justifies the additional amount of work involved. First, by removing the OEM CCV you will by removing an insignificant amount of weight (a couple of ounces) from your BMW, and second, you gain much easier access to the dip stick tube area for cleaning and removal of the dip stick tube and installation of the drain back hose.
If you follow these instructions and leave the OEM CCV screwed to the bottom of the intake manifold it will IN NO WAY remain connected to your new G.A.S. CCV or any other part of the engine. We chose to provide our instructions without manifold removal to make the procedure simpler for use by people with a wider variety of skill levels.
If you have the time and the skills and prefer to remove the intake manifold, go for it, I have no reason to discourage it.