Thank you all, I finally solved it. After a couple of weeks of taking apart every connector on the car and inspecting, cleaning, and re-connecting, without success, and listening to all the great advice I've received on this board, I finally found the problem. This is really hard for me to believe but, I reluctantly replaced both the O2 sensors yesterday thinking that there is no way that both of them could go out at the same time. But guess what? No more lights (crosses fingers). Car runs like new. No more stalling or galloping idle speed. What are the chances that both sensors would go out at the same time? Is there something that could make both of them do this? I bought the Bosch universal ones that you fit your original connectors back on to. Sweet baby Jane, she's rollin good now.........
Bosch # 15727 oxygen sensor. Make sure you look at the part # on the new sensors, not just the new box, because I got one that was marked --725 instead of --727. You have to use your original elec. connectors for the new O2 sensors. Bosch gives you a wire splicing kit and instructions. Simple to do. Just make sure that you keep both of them relatively the same/original length.
One more thing. If you want, you can replace the sensors from the top side of the engine. There's a few options for getting a wrench square on the sensor. 1. You can bend a 22mm open end wrench at 90 degrees to fit in there.(that's what I did) 2. You can possibly get a shorty 22mm wrench in there.(not sure) 3. Cut the connectors off the old sensors about 4 inches from the end so you can put a box end wrench over the sensor. (not recommended by Bosch because of determining the length of the original wires.)
The additional ground wire clamped to the right O2 sensor cured my CEL 1-4 error code of 1211 this week, just as a data point for future reference.
