Thank you very much for your responses.
The multimeter is brand new. It's one of the Sears ones recommended in another thread. Today I verified the result with another multimeter by a different manufacturer. KOEO current was +22.5mA. Upon cold startup, current started out around +9mA and slowly decreased. I disconnected the oxygen sensor, and it didn't go to zero. It kept decreasing as the car warmed up, leveling out at around +2.6mA. After leveling out, throttle did not affect the current. Upon plugging the oxygen sensor back in, the reading fluctuated between around +1.7 and +2.2 (different from yesterday, interestingly enough). Disconnecting the oxygen sensor left the value at 1.7. It seems that when the sensor is disconnected, the EHA doesn't go to zero, but "sticks" at the value it last read from the oxygen sensor. Even more interestingly, I shut off the car, and KOEO current was +21.7mA!

Can the EHA be "sticking" like that? Or is something else going on? I am in Oregon and, unfortunately, my DEQ report doesn't include the O2 reading. The test was right after a highway drive, but it did idle for a few minutes before the actual test. As for decarbonization, I have some Seafoam I can run through it. Has anyone done that? If so, what vacuum line did you use to put the Seafoam in?

Thanks again

Michael