This is...maybe I'm a little emotional, but this is a revelation for me. Thanks!
I have perused some other sites, looking for answers--sometimes they don't load fast enough and I have a short attention span. But I have seen enough online to see that problem (rough idle, misfires, and so forth) is common and yet not many people seem to know the answer.
My intention then is to change the MAF, and, with 122k miles on it, at least check the plugs and wires for wear. I'll report back when I get to it--it may be a few weeks.
Thanks again!