EGR valve question

Yeah, you usually can get away with cleaning it. Since you'll have to remove the valve anyway, take it off and give it a good spray down with carb cleaner or throttle plate cleaner. Be sure ot get up inside, as your issue os probably gunk that is preventing the valve from closing all the way when the car comes to a stop. If you have a vacuum tester, you can verify that the valve will close all the way on its own before you reinstall it.

Nope, just pull the vacuum line off the top of the EGR valve and pinch it off. As long as you can shoulder the moral burden of emitting more oxides of nitrous than the EPA wants you to, you'll be alright.

Ok, you have said that disconnecting the EGR solved the dying engine problem Ok, that means the valve is closing. This also means the EGR valve diaprham is somehow getting vacuum to open it when it should NOT. So your valve is ok, from a sealing standpoint. I would ask you to review all the EGR related vacuum plumbing, valves, etc to find out how (probably) manifold vacuum is reaching the EGR and opening it at closed throttle.

Oops--the part I removed, and which at least temporarily solved the dying-engine problems was NOT the EGR valve, but the EGR Vacuum Modulator. Sorry for the confusion. Does this pretty much indicate the part is bad or clogged?

EGR vacuum modulator VENTS ported vacuum from the throttle valve (ultimately) to atmosphere UNTIL ... there is a small amount of exhaust system back pressure present (a signal of engine loading). This back pressure pushes up on a diaphragm which in turn closes off the vent, thereby allowing ported vacuum to reach the EGR valve (hence the EGR valve opens).