The IAT stands for Idle Air Temperature. Basically its a temperature sensor that the engine uses to make its decisions. Im not sure about the resistor trick, but i would assume it changes the voltage value and therefore alters what the computer reads. I could be wrong, but i think they came about the same time as Mass Air.
[QUOTE]Originally posted by Vortex
[B]The IAT stands for Idle Air Temperature.
IAT stands for Intake Air Temp . It senses the temp of the incoming air.
The PCM uses the IAT value, to adjust fuel , ADD FUEL if it is cold
take fuel away when it is hot. The resistor fools the PCM into thinking thats the air is colder than it really is. So there is more fuel.
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