[shorod]

How have you narrowed to the MAP or MAF? I believe your Explorer has a MAF, not a MAP. But, your symptoms sound more indicative of a bad Idle Air Control (IAC) which is a pretty common issue with the Explorer. You could start by removing it and making sure the passages and valve are clean. If clean, there's not a lot of chance cleaning it will remedy your issue, you probably would just need to replace it.

Does it run smoothly if you just barely keep the throttle open, or is it pretty rough? Has your fuel economy dropped at all recently? Does it tend to idle fine once the engine is up to temp?

The Mass Air Flow (MAF) sensor measures the amount of air entering the throttle body so the computer can adjust the fuel injector pulse width to maintain as close as possible to stoichiometric air-fuel ratio.

-Rod