I have a 2003 Element the engine light came on. Advanced Auto parts says its code P0141, O2 sensor heater circuit bank 1 sensor 2. However there are 2 sensors 1 is post cat the other pre cat. Which one do i change
If you trust advanced auto, its description sounds like the cat monitor sensor or the second one.
You only have one bank on this engine, I would imagine its a generic reader reading the standard oboII codes.
Erase the codes and see if it comes back before you change it.