92 Lumina 3.1L ... Part of the EGR system? My haynes manual doesn't tell me much... can anyone tell me or help explain this error code to me? I can't even find the damned EGR valve :o

Here is an article on the basics of EGR function. Some of it doesn't pertain to your particular vehicle, as your's has an electronic EGR, where the author is describing a vacuum operated system. Your EGR valve is mounted on the back of the upper plenum near the throttle body. It is a 3-solenoid electronic valve that is held on by 2 bolts.

www.sethirdgen.org/egr.htm

If you are lucky cleaning may help it.
But about half the time the egr valve will be bad but clean it and look over first.
Here is a link to testing it.
http://members.troublecodes.net/crunch/egr.pdf
Good luck and let us know how it goes.
MT

good suggestions guys. another thing that wasnt mentioned, well maybe but not made clear, the passage going into the intake might have a nice size booger blocking it up and setting the code. a coathanger, patience and time should get it cleared but be careful to not let a lot of it drop into the plenum.