I disconnected the vacuum line to the secondaries about 6 or 8 months ago, and the sulfur odor happened. i drove the car for about 10 minutes, reconnected the secondaries. a day or two later, i disconnected them again, and the odor was gone. i think it has something to do with teh buildup that happens in the secondaries. when you remove upper intake manifold and look at the butterflies, you can see a gunky buildup that is not present on the primaries. my theory is that during aggressive driving, the secondaries are open more and the gunk has the chance to burn a little bit with the added airflow. that produces the sulfur smell. once the gunk is burned away, the smell leaves.
that is my theory, although i admit that after driving with the secondaries disconnected i havent gone back and looked to see if the gunk is still there or not.
