I am at a lose here. My 15 year old son just used all his money to purchase his first car, a 2010 equinox LS 2.4l. It was in a small front end accident. Broke radiator, condenser and cooling fans. We have replaced all that and now are getting a Po131 low O2 sensor code. I pulled the schematics and checked continuity and voltages and them seem fine but I'm not sure. I have pics of my findings. I am slightly concerned it is a head gasket and that is way I'm getting a misfire but compression readings came back ok and I don't see coolant getting less. I do get quite a bit of smoke out the tail pipe and it runs rough. I also changed the plugs and O2 sensor 1 with AC Delco.

 

Could it be that ground splice at J108 is open to B1S1? Looks like it from your KOEO testing if I'm reading it right. How about that PNK/BLK where does that end up?

 

Thanks for the reply.

Just a few minutes ago I cut the three wires at both ends of each connector and ran new wires in case there was a short in the loom. The pink black wire is measuring full 12 volts so I left that one. Same error code. Ugh. The only thing I can come up with is that the computer is faulty. I know it's not common but maybe in the accident it took a weird hit. One would think there would be more error codes. Idk. Thanks in advance.

 

Not every electrical fault is a "short". If you have 12v after the load it might be that a ground is open. Don't have the full diagram so can't really see. Good luck.

 

I would also add that load testing a circuit is incredibly important. Short and open aren’t the only things either. If you have a partially frayed wire that can’t carry a load then it will cause faults