In article >,
says...
> I had this just recently - car would idle at ~~1500 or 2000. And you
> could tell the computer was trying to keep it there.
>
> Coolant temp sensor.
>
> On the older 4 bangers, you can swap the ATS and CTS cause they're the
> same. Quick and free. I don't know what the air temp sensor even does
> besides make the EPA happy...
>

The ATS (on most cars) is one sensor that will keep the ac from kicking
on when its below 40deg to prevent you from destroying your compressor
among doing other "good" things. This isnt 1978, emission control
devices do little to rob power, if anything they help make it when they
work correctly.