I finally found the reason I've been having so much trouble with the car. I've got a vac leak at the EGR inlet on the SC housing. I'm guessing the leak is where the tube meets the inlet, or somewhere close to that, but I don't know if it has a gasket there, or if it's just metal to metal. I got the most reaction when I sprayed the carb cleaner on the outside of the bend where the tube enters under the TB. My question is: What the heck should I do? Can I weld/braze the area? Can I put a gasket or RTV where they meet?