Most O2 sensor codes are caused by an underlying fault and not by the o2 sensors themselves. Tell us which codes you're getting, and what symptoms you're experiencing when driving the car, so we can help you troubleshoot the problem.
Is the engine down on power? No
Does the engine misfire, bog down, hesitate, stumble, or run rough? No, but it did. That is what caused the check engine light to come on. I had three O2 sensor codes and a couple misfires. After changing all four sensors, the coil pack, wires and plugs all was better but O2 Sensor codes didn't go away. So i cleaned MAF and Throttle Body and they're still coming up.
Does the engine have an uneven idle or stall? No
Have you done any mods? No
Does the ECU have an aftermarket tune? No
More information would be helpful.