StevenZ,
Thank you for your response. It appears that I do have an exhaust leak where what it appears to be, like a flexible coupling, just under the driver side seat. I do believe that is the cause of the exhaust/fuel odor I've been smelling.
But, even though I have replaced the EGR valve since my initial post, it stills seems to idle a little rough when stopped, after it reaches normal operating temperature. It's not as bad as it was, but it's still doing it.
So, after replacing the EGR valve, the fuel filter, the fuel pressure regulator, and plugs and wires, I'm at a loss as to why it's still idling rough.
Any thoughts on that?