Mopar friends, I need your assistance.

You need to have the ability to look at scan data and preferably something that can graph........there are plenty of cheap scan tools that can accomplish this.......forget about downstream O2 sensor and concentrate on the upstream and when it acts up running rich it should be reading .7 ish to around a volt which in that case it would be doing it's job of reading the exhaust stream, but if it's low voltage and by that I mean .1 maybe .2 volts then it could be a sensor that is stuck lean and the computer is compensating for what it is seeing from the O2 sensor. O2 sensors can be quickly and easily checked for normal operation by inducing a rich or lean condition into the system.....if you have one that reads rich and you don't know if it's rich from something else or the sensor is stuck all you have to do is induce a vacuum leak and the sensor should respond immediately with a low voltage reading. Conversely if you have one that is reading .1 to .3 ish range and not changing from that state you can give the vehicle a hard snap throttle and you will see a quick reaction to lean and then a shift to rich......this way you can tell if the sensor can react to something induced.....you could also introduce propane into the system to richen it up and see if the sensor immediately reads it. Start there......if all that checks out then I would look at MAP sensor data.