UPDATE: 6000 mile oil change: 6000 miles since changing the intake manifold. There was about 1/4 cup of oil in the catch can. I can't freaking believe the PCV orifice is clogged again after only 6,000 miles....this is unacceptable!!! GM needs to address this problem!!! Removing the intake manifold to clean the PCV orifice every 6000 miles is way beyond what I would call "normal" maintenance!!