Thanks SubSailor. I'm starting to think maybe my MAP sensor is kicking out on me on sharp bumps. I've softened the preload one more click to help with that, and the ECU and PC is strapped down good.
Madbuyer, I've already gone thru all the connectors on my bike, except a few like the injector connectors and a couple others that are buried deep.
I dug down to the MAP sensor today, connector slid apart nice and smooth, dielectric grease still healthy from last time. the connector looked clean, so replugged it, and put it back together. Checked vacuum hoses with my Mighty Vac, inspected the wiring, and finally checked voltage across the wires per svc manual.
Erased codes, and got a clean slate now. Did some cleaning up of wiring routing, eased the tank down, and rode her around a bit on some bumpy roads. No codes yet.