Air Temp Sensor
An air temperature sensor is used on fuel injected engines. The purpose of an air temperature sensor is to help the computer calculate air density. A change in temperature changes the resistance in the sensor. Simply stated, the higher the air temperature gets the less dense the air becomes. As the air becomes less dense the computer knows that it needs to lessen the fuel flow. If the fuel flow was not changed the engine would become rich, possibly losing power and consuming more fuel. The temp sender is generally located in the air inlet tube or the air box. The wire running to the sensor can be disconnected then the sensor can be unscrewed and replaced. Some aftermarket companies trick this sensor with a resistor (false temp reading) to make the engine run richer. If a engine has been tuned lean this trickery can show mild power gains.