You can do this for about 50 cents. Go to Radioshack and get some resistors.

What they do is go inline with IAT sensor and fool it (thus the resistor) and makes the engine run richer.

This works if you have a lot more airflow but not on stock enignes, it will just waste more fuel.

Also, the ecu compensates for it after a while since the 02 sensors are reading that it is runing rich plus so it leans it back out.