On my 2004 Ford Thunderbird, I have a check engine light with the following codes: P0133 "Ox Sensor Circuit Slow" Bank 1 sensor 1 and P0153 "Ox sensor circuit slow" Bank 2 sensor 1. I had the sensors replaced about 2 years back with Bosch sensors. I ran my problem through 3 different AI programs and they gave me 3 different answers and said the other AI suggestions were incorrect. Any idea what might be causing both sensors to trigger a "slow circuit"?

 

If you see the circuit problem then it's the wiring issue and not the sensor itself.

 

For what it is worth,,,,,,,,,get one new o2 sensor ,install it, and see if the code for that bank goes away. You could be going on a wild goose chase looking for something that may not be there..