warm the engine up to operating temp and take a volt reading at the O2 sensor. If the reading is locked, it is possible that your O2 sensor is dead. You can also see if the computer has the ability to respond to the sensor signal by: grabbing a hold of the signal wire (in one hand ) and touching the positive terminal of the battery with your other hand, then look (on your scanner) to see if the O2 volts are rising and the engine begins to run lean. So that coupled with a locked reading probably points to a dead sensor.
