First, thanks for all of the suggestions--I'll be trying as many as possible(or needed) this weekend. I've been driving the car all week and the lite has been on. Aside from the stumble when the car is almost at operating temp. it has been asymptomatic.
Until today. I started it up and the light didn't come on. I drove about 10 miles, and while driving a steady 40 mph on relatively flat road it came back on
There, once again, were no other symptoms. Does this give anyone a better diagnostic clue? -Ed