The wire harness connector fo rthe O2 sensor should be of the same color as the lead on the sensor, I believe. A single wire connector as GM uses a single wire sensor.
This sensor being unplugged probably won't be the culprit of the engine not running for after 3-4 minutes, but one never knows. I believe if the sensor is unplugged, ECM goes to default value and contines running.
I would check the fuel pressure to see if the pump is still working after time. Whether you have a TBI unit, TPI set-up, there is a Schrader valve to check pressure, the valve looks just like the tire valve stem. After the engine quits, remove the cap and press the valve, if fuel comes out squirting, then the fuel pump is still working. If fuel dribbles out or less, either the fuel pump itself is bad and/or the fue;l pump relay has burned contacts internally and relay needs replacing. Its located by the driver's hood hinge, a black box plugging into a socket. Also, a plugged fuel filter will give trhe same results.
If you don't find any treasures at www.thirdgen.org
, get a Haynes manual from the local auto parts store for the car/model and read up. Its better than nothing.
Another clue, listen by the tank for a hum when the ign key is turned to IGN, pump runs for 2-3 seconds. After engine quits, listen for the fuel pump hum again, hum not there, either bad fuel pump or bad relay. Check f/pressure valve again.