<_< Thanks everyone. I'll have an autopart store re-check the code. I have a suspicion that it might not be the O2 sensor that's wrong this time. Do you know which auto store would do this - Autozone, Pep Boys. I'm in the Chicagoland area.
Or another thought is that the wire that connects to the O2 sensor itself is faulty. I failed to mention that before the "check" light indicator came on, I had some work done by CarX - replace cam cover gasket, cam seal, water pump and timing belt. When I got the car back, I noticed that the mechanic did not put the plastic housing of all the wirings together properly. This is the plastic cover of the fan belt that goes around to the edge of the cam cover closest to the firewall. It looks like while working on the car, he cut the wire of the O2 sensor. The wire appears to just have been tied back together.
When I replace the O2 sensor, I used the same wire and spliced it together. It is possible that the wire is not the right one. I can't verify this because it is just a single wire that's sticking out of the plastic housing. I will have to open the housing to see if it is the right one. Even if I did, I would not know if it's the right one.
Does anybody have any suggestions.