Update in case anyone is following...
Check engine came on again, along with rough idle. Drove couple miles home. Went out to read it, light off.
I flew down ~ a week ago to drive 350 miles home with my daughter. No problems, car was happy to cruise @ 75-80 MPH. Got 25 mpg.
I checked grounds, inspected connectors, replaced a leaky vacuum line on fuel regulator & cruise control. Couldn't budge the PCV, probably installed in 1992 in Japan. I managed to run some throttle cleaner through it. It behaved fine all week, until Friday (the rain returned). Check engine light came on after start, same 3 codes. Restart, light off
. Went to lunch, then home.
Checked everything again... Just because: I removed & cleaned body ground by battery tray. Disconnected & cleaned: E1, E2 & single connector ground from harness to firewall. Except for the firewall ground, which looked like it had some yellow/brown goop, probably some type of dielectric grease (also all over FWD fuse socket), the pins looked clean & shiny. All connectors gave a satisfying snap when plugging back in... Also fixed broken mount on main fuse relay box.
No problem so far, but it's really intermittent... just keeping my fingers crossed. The car goes back to college in a couple of days.