Okay, so the breakdown on O2 sensors is O2S11 and O2S21 are the O2 sensors the PCM uses to maintain the air:fuel ratio at 14.7:1 to keep your engine running at stoichmetric, or perfect burning for an internal combustion engine. O2 sensors O2S12 and O2S22 are the O2 sensors that read the effiency of the catalytic converters and do nothing else. For vehicle performance O2S11 and O2S21 are the O2 sensors that count. Having said that, I have included for you in the diagrams down below the possible causes for DTC P0161, the engine management wiring diagrams with the O2 sensor heater wires highlighted for you, and lastly the pinout diagrams for all 4 O2 sensors. Please go through these guides and get back to us with what you find out. Also, if any splicing to the O2 sensor circuits is to be done, it must be done on the vehicle wiring harness side. If you cut into any of the O2 sensor wires then the O2 sensor is ruined and will need to be replaced. I hope this helps.
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Tuesday, March 17th, 2020 AT 8:06 AM