Thanks onehundred80.

I pulled the RCM last night and the air pump relay had very minor black residue on the contacts. I used some isopropyl alcohol on a small head toothbrush a few times, dried it all then took a new $5 bill across all the contacts.

Put the RCM back in the car and no CEL !!!

Checked the OBDII this morning, no codes. Holding my breath until all the monitors run through their respective cycles but I'm cautiously optimistic

I feel silly not checking the air pump relay in the RCM since I knew all about it from years ago but since I heard the whine from the air pump on cold start conditions I assumed the relay must be OK.

After cleaning the RCM last night I took a drive during which I heard the air pump run for 10 seconds or so while stopped at a traffic signal after only driving 3 or 4 miles. I thought: what? that's unusual. Maybe the relay was just working properly on cold starts but once the engine warmed up a bit the slightly dirty relay wasn't making proper contact and the air pump didn't run as needed (at idle at stop lights?) resulting in the p0140 code re-occurring.

I will report back in a few days when the monitors finish incrementing .....

P.S.: it seems the codes all cleared when I removed and reinstalled the RCM. Can anyone confirm this? If true, no need the disconnect the battery (losing radio programming) - just pull the RCM ???