Engine code P0131 fix O2 sensor removal tips replacement. Stretched wire harness causes oxygen sensor low voltage check engine light. How to replace remove install. Featured vehicle 2012 Ford Focus. Bank 1 sensor 1 B1S1. Bank one sensor one upstream. Had to heat the sensor up to remove which is the case most times around these parts. #mechanic #p0131 #howto #automotive #oxygensensor #fordfocus #carlsgarage | Carl's Garage