If you can get a hold of a good manual (factory, Mitchell, Motor, or equivalent), you will find circuit "pinpoint" tests for each code. There's a file called gtest.pdf floating around the internet (google for it) that is taken from Mitchell for a '95 Explorer that has a lot of information in it, most of which should apply to your '94. Better yet would be to go to the library and see if they have the proper manual for your year Explorer.
In any case, it's important to remember that codes point to circuit faults, not sensors. While it's true that codes can be caused by bad sensors, they can also be caused by a bad wiring connection, broken wires, shorts, etc.
The set of pinpoint tests I have (the aforementioned gtest.pdf file) shows that the CMP is the input for the CID circuit. After verifying that the 214 comes back consistently(as you have), they have you verify all the wiring between the CMP and the PCM (get a wiring diagram). When you eventually get around to checking CMP output (step 8), it is tested using an AC voltmeter. I must point out again that this file was written for a '95 Explorer, and I'm assuming that your '94 is the same (which isn't the same as my '92 which doesn't have a CMP).
