[zerodameaon]

Take some throttle/carb cleaner and spray it at individual lines. If the engine bogs down its a bad line. As for the BPT to EGR hose, its obvious when you put your hand on the hose, they tend to rot all the way out. Adjust your idle, I have steps in my SIG on how to do so.
Replace the O2, its not to bad a job and is pretty cheap if you get the universal and just crimp on and heat shrink the wire, all parts should be included. And before you go in to do the check make sure to get the car nice and warm, and see if they are nice enough to run a pretest.