If that is 'Intake Air Sensor', then it will make the car think the air is warmer - so I suppose that would cut down on mixture enrichment when the car is cold.
It might also lean the mixture down, but I'm not sure of this. If your car only senses the volume of air with another meter (MAP sensor / mechanical airflow meter?) then if the car thinks the air is warmer, it will assume it is less dense, therefore less oxygen, therefore will inject less fuel.
The advantage of this would be increased fuel economy while cruising, with vastly increased nitrogen oxide emissions, which harm the environment. The disadvantage would be that, when the engine begins to enrich the mixture, there would be a point where you are running at stoichometric when it should really be enriched. This would mean that thrashing the car could possibly cause more stress on the engine than it should.
I may be completely wrong here - just my guess from basic principles
__________________ Team GasMisers5 - #1 for first three rounds of the original GS Fuel Economy Challenge
Miles displaced by e-bike since 1 Jan 2008: 62.6 (0 kWh used)