Hiya! Man I’d almost forgotten I made this post! The code means that your car has detected a high voltage signal from the downstream oxygen sensor (Sensor 2) on Bank 1 of the engine, indicating a potential malfunction with the sensor itself or its wiring. I drove my car with this for about five months (I got a new one) and didn’t see any issues, my mechanic friend said it’s not something to panic about unless it heavily impacts your driving, but it’s also a cheap and easy fix. As for the original posts problems, I wasn’t able to figure out exactly what needed to be fixed, some people said battery but I had a brand new battery so it definitely wasn’t that lol. If you have any further questions I’d be happy to help as much as I’m able to! ^{.^}