Many thanks to Petrified Rabbit & 06T200 for sticking with me on my Check engine light problem .
Like you guessed it was a very fussy ECU that wanted a few more degrees temperature , before this I NEVER would have thought 3-4 degrees would make a difference .
Also one by one the Universal O2 sensors failed ( 2 for $30 on ebay , I should have known better ) and I replaced them both with Genuine GM AC Delco O2 sensors .
No check engine light now so hopefully in a few days of the ECU recycling we can get it thru Emissions for another two years .
Thanks again . old n' slow