Swaped out the O2 sensor today. The old unit would rattle when shook. The idle hesitation is gone. Looks like that was it. Many, many, thanks Benzmac and Stevebfl!!!!!!!
Can't wait to see if the milage is back up to twenty MPG (if not I'm going to start driving my 6 MPG 428CJ Fairlane convertible around because it's a lot more fun - at least in a straight line).