Ok, when it wasn't so cold out 30-40 deg, I was getting code 11 /upstream O2 sensor/, but i never had any problems and i was getting good milege. I'd clear the code, but it would come back after a day or two. Now, when it's 8 deg outside the CEL hasn't been on for 2 weeks. What's going on? Can anyone explain it? Sensors are 3 months old.
