Thanks for your responses to my coolant sensor question. Funny thing about trouble codes, they ain't always right.
You two got me thinking, I mean the old fashioned way to check and see if something is working is to unplug it and see if it's runs worse, right?
Anyhow, it turned to be the Baro Sensor which had come loose. It fits into the air filter box with a rubber donut gasket that needs to seal. I must have banged it around when replacing the alternator.
thanks.....john