How much you guys know about o2 sensors

[Justin95GSR]

Ok I recently had a busted o2 sensor that was causing a check engine light. The car was running ok but not best cuz I was losing to people that I was previously beating. Now I got a new one on today and the CEL isn't on anymore and it feels like it's running STRONG as hell. I read that when the CEL is on that it makes the car run in loop mode but I was just wondering if you guys new exactly how much having a CEL hurts your performance vs. not having it on.

[LuxoM3]

IN a few words...the O2 sensor helps the Cars ECU determine the right mix of fuel and air...

so imagine if the O2 doesn't want to work anymore...

then the car is not making the most power possible...

That's about it.