bank 1 sensor 1, bank 2 sensor 1, toyota mr 2, repair manua

i have a 2000 Toyota MR-2 the codes translate as bank 1 sensor 1 and bank 2 sensor one low voltage heater, i need to know what sensor they are (before or after cat) and which one of the before cat sensors it is that needs replaced. (not even the repair manual tells what one it is)

Answer
    The codes refer to the sensors in front of the converter. I don't know what they mean by bank 1 and bank 2.  This usually refers to the left and right sensors on a V engine, which the MR2 doesn't have.  So, you should just have to replace the upstream sensor and be good to go.  That business about the low voltage heater makes me think that the computer is sensing that the heater built into the sensor is not working.  Make sure that you check the wiring going to the sensor, it might be that and not the sensor itself.
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