The o2 sensors for a 2011 Chevrolet Aveo are situated in the exhaust</br> on each side of the exhaust system. The O2 sensor is intended to ensure that the blend of air and fuel in the motor is right. In the event that there is a lot of either</br> the motor is running rich or lean. If so then</br> at that point</br> it won't work effectively. For the time being</br> this will make You have more awful gas mileage</br> yet in the long haul</br> it can put additional wear on Your motor and cause harm. O2 sensors are modest</br> around 30 bucks</br> so You really want to supplant them assuming that they turn sour</br> or hazard greater installments later.