97 Malibu 3.1. The Check Engine light is on along with very hard 1-2 shifting. Thanks to an old thread here the IA temp sensor appears to be the problem.
There are three different possible sensors in a row. The first goes into a black square plastic thing about half the size of a candy bar. The black plastic thing is attached between the 2 metal flanges that connect the airbox and the accordian rubber. The second possible sensor plugs into the side of the accordian rubber hooking the airbox to the engine. The 3rd plugin is on the plenum right by where it hooks to the accordian rubber. I thought this last one might be the mass air sensor but I don't really know much about injected engines. My guess is the one going directly into the side of the accordian rubber. What is the actual answer?

its in the side of the rubber ducting
it only has 2 wires in the plug. this can be checked for power with the key on 5 vdc. If no pwr the problem is in the wires or pcm
check resistance across the pins on the sensor 50 degrees is 5600 ohms 80 degrees is about 2800 and 212 is 176 if u heat the end in hot water