I hope this works for you, you've been like a dog with a bone, sensors, ECUs are OK until you get one that seems to have a mind of it's own. I have a lamba sensor with an intermittent fault (I think) EML comes on, put pscan on (I'm a novice) both sensors seem OK so clear the fault everything's fine for a day, a week, a month or more then ping EML on. I've cleaned the connectors with contact cleaner and it made no difference seems I'll have to wait for it to fail entirely or change both and throw one good one away.