1995 Pontiac Firebird Mass Air Flow Sensor

So I have documented an overheating problem on this site over the last month or so. Thank you to all that have helped me. I have another situation. I have replaced the radiator hoses and the radiator cap, and the temperature has gone down. Now though, the fans don't come on. As I think on it, the fans have not been on for a while. So I raised the car and checked underneath. There was a small metal box under the driverside turn signal in front of the wheel. The repair manual does not mention this part, and it doesn't have any identifying markings on it. What I did notice was that there was a plug hanging in the area that someone had obviously tucked under the cowling. Turns out that the small metal box was missing a plug exactly the same size, so I plugged it in. When I started the car the fans came alive and the car wouldn't overheat. Which brings me to my problem, there is a plug on top of the Mass Air Flow Sensor. When the car is running and it's plugged in, the fans don't come on, the car heats up (@225-230+ degrees), and the service engine soon light comes on. When I unplug it, the car kind of bogs down for a second then comes back, the fans come on, the car cools back down to normal, and the service engine soon light goes off. It doesn't make any sense to me, I don't understand the connection between the two and the shop manual doesn't say anything about the sensor. Do I maybe have a bad sensor? Could it be something else? I could really use some help.