Sometimes I think we lose sight of what those diagnostic codes mean. Sometimes a code could mean the sensor is defective, but the real intent is to indicate that whatever that sensor is monitoring is out of limits. So to me the next step is to trouble shoot the causes that would trigger the fault.

For example I had an indicator that indicated my O2 sensor was source of the scan and after several years and several O2 sensor replacements; I found my fuel pressure regulator was the cause. I would occasionally allow high fuel pressures and the resultant rich mixture condition

Just a thought.