IAT Sensor - Intake Air Temperature Sensor

The Intake Air Temperature (IAT) sensor determines the air temperature inside the intake manifold. Resistance changes in response to the ambient air temperature. The sensor has a negative temperature coefficient. As the temperature of the sensor rises the resistance across the sensor decreases. This provides a signal to the PCM indicating the temperature of the incoming air charge. This sensor helps the PCM to determine spark timing and air/fuel ratio. Information from this sensor is added to the pressure sensor information to calculate the air mass being sent to the cylinders. The IAT is a two wire sensor, a 5-volt reference signal is sent to the sensor and the signal return is based upon the change in the measured resistance due to temperature.



Fig. 1: The IAT sensor is located in the air cleaner outlet tube-2.2L engine and 2.4L engine.


By relocating your IAT (Intake Air Sensor), you can fool your car's computer into thinking that there is more cool air entering the engine than there actually is. This causes the engine to increase the amount of fuel that enters the cylinders, as well as altering the timing (advancing it 3 degrees), thus creating more power. This mod is especially beneficial when used with an aftermarket air intake system. Please note that there is a tradeoff with this mod: your car will loose fuel economy.

Method

1. Locate your IAT. It is a small sensor found in the S-Tube which leaves the front of the engine and into the airbox. Carefully remove this sensor by pulling it while wiggling slightly.
2. Cover the hole you left in the S-Tube with some sort of tape (electrical tape would be a good choice, since it's black, as is the tube). Ensure that you completely block the hole, otherwise air will enter thru that hole unfiltered (which could cause engine damage later on).
3. Relocate the IAT sensor to a suitable location in a grill near the front of your car. Be sure that you route the wires away from any possible sources of heat or where it could rub against another part, as this could cause the wire coating to wear off, thus causing a short circuit. Cavalier Z24 owners may wish to place the sensor behind the inserts near the fog lights, whereas Sunfire owners can place it anywhere in the hex grills. Remember, the idea here is to get as much cool air flowing over the sensor as possible. Don't place it behind your license plate or someplace where the air won't directly contact the sensor, as this defeats the purpose of the mod!