The line is right on top, very accessible and visible, and runs from the plenum, which is engraved 3.1 something, around the back of the engine by the coils, and down toward the inner fender area, driver's side. It appears to feed something into the air to mix with the fuel, and when I disconnect the line at the plenum (upper intake manifold) it runs REAL badly. If I plug the hole with my finger, it resumes its normal idle (cold=fine, warm=suck). All I can figure is that the line must be plugged somewhere before the break (and therefore simulating the finger plug), as it is certainly not getting fresh air, and I know it is not getting what it is *supposed* to be getting, because the line goes nowhere.
The sensor is a thermistor, so it will (in this case) drop resistance as the temp increases. Haynes gives the chart, and the values I should (roughly) see, and working in electronics, I know how to test a normal thermistor. But for some reason, this has three pins. I just don't know the pinout of this sensor.