I am going to expose my ignorance, here...but, I don't remember a Mass Airflow Sensor on an NA IDI in 1994.
There was a BARO sensor that would send a (relative) elevation input to the TCM., though. mounted on the (ahem) firewall and had an open port to sample atmospheric pressure, turn it into a frequency signal and send it to the computer.
Replacing it might fix the code, but, the 'out of range' warning might be coming from a circuit signal that does not make sense to the ECM.
It is a three-wire sensor. Power, ground and signal return.
Known as B+, Neg., and the signal sent back to the controller.
If you want to possibly save some money and time and know better that things are ok if and when you replace the sensor with a new or good used one, do this....first, break out a good voltmeter and set the range to Volts, DC, 0-20 volts.
Ground the black lead first.
Key on, engine off pull the connector and touch your red lead to each of the three wires until you find a DC reading...what is it? You are looking for 4-5 VDC.
One of the other wires should be ground...no more than .25 VDC.
The last one should be backprobed with the connector back on the sensor and set your meter to frequency (HZ) and record the reading.
If the power and ground are good and the frequency is relative to the assumed baro pressure for your elevation...(are you a mountain man or a flatlander?) then the sensor is ok.
If something is wrong with either power or ground then fix that before you get another sensor.
If the power and ground is ok and sensor reading is way off the scale...then get a known-good sensor and plug 'er in.
Wipe codes, wash, rinse, repeat.
Let us know how it works out.
