If there's enough slack in the wire, push/pull the rubber grommet from underneath the car, where the sensor wire goes through the floor pan. That way you can look inside the car, & see which wire is the proper one.

 

I should have pointed out that access to secondary O2 sensor will require elevating the car on Jack stands or front end on ramps.

good luck

 

I replaced the secondary o2 sensor and the light went away. It's been gone for 4 days now and counting. (Knock on wood) Took it to the inspection center and it passed! Going to keep an eye on it in the future and see where we go from here.