EGR wonderings...

Recently, my '83 3.8 convertible has started acting funny. When I'm driving, I can push the gas pedal to the floor, and it sounds like I'm running on half of my normal 6 cylinders. I let off the gas, and the engine clears right up. A buddy at work that knows a thing or two about cars took a peek at it and said it was my EGR valve that needed to be replaced.
As a non-mechanical type, I was wondering if anyone could explain what that valve does, and whether or not it would be suitable to put a delete plate in or just replace the valve.
Thanks in advance!