Nope. There is a tuned map, then there is the 02 feedback in low load area's to help with the fuel economy but this only works if the sensor is relaying the correct info back to the ecu,
If the sensor tells the ecu its running lean (due to a bad sensor) then the ecu will richen the mixture up giving it worse economy.
Where as if the sensor is not giving feedback the ecu will use the tuned map which is better than bad feedback from a dud sensor