The PCV pulls right out of the valve cover. There's a little valve inside that should move up and down pretty easily. They get pretty dirty with carbon and junk, so you can take some carb cleaner to it if it's bad. I don't know how you can tell if that's the source of the problem other than cleaning it and seeing if that valve inside moves freely.
I had a vacuum leak on mine. It was the TB gasket. It used to die at intersections all the time, and going to throttle, but never once it got going, so I don't know if that is the problem with yours. I've never had major issues with mine without it throwing a code, so that makes it tougher for you to track down. Does it idle smoothly? When I had the vacuum leak, it used to idle a little rough, and the whole truck used to vibrate a little bit.
At this point, I'm just working out the little kinks until I find the source of the problem so it's added to the list. First thing in the morning, I'll go pick up a can of brake cleaner and a can of carb cleaner, and try it out. Thanks for the suggestion man. As for your question, it idles like hell sometimes, then other times it's smooth as butter.
Earlier today when I picked up my CTS from O'Reillys, I hopped in, cranked it, it started and went up to like 1,500rpm, then dropped down TOO low (motor was already warm) and just shut right back off. And off of red lights, sometimes i have to give it ALOT of gas (think, like, half throttle) to keep it from shuddering so bad it dies.
EDIT: I should also mention that when I rebuilt the TB, i was too lazy to pull it off and replace the large gasket underneath. I have one laying around, might as well do that too to knock it off the list.
