[BNaylor]

Not clear by your post but did you replace the thermostat?

The engine coolant temperature sensor (ECT) could affect when the PCM module switches to closed loop mode from open loop mode after proper engine warmup. The 02 sensor input is used in closed loop mode only. Note: The same ECT sensor is used to provide the engine temperature reading to the temperature gauge at the IP Cluster so is that reading proper? Should be around 195 degrees after sufficient engine warmup and weather conditions.

I didn't see it posted but what is the code for the cooling sensor fault?

One of the enabling parameters to set the P1133 DTC is coolant temperature being closer to normal or greater than 50 degrees C or 122 degrees F so it may not be related to the reason why you are getting the 02 sensor DTC. The P1133 DTC means you have a lazy bank 1, sensor 1 02 sensor or slow to respond.