ok i justrecently bought a 1994 explorer XLT.. when you press on the gas the rpms go down... but when not pressing gas it is just fine. the guy i baught it from said that it was the The Catalytic Converter ... cut it off and it still does the same thing. it takes forever just to get up to 35 mph. what is the problem

 

Suggest you to scan the computer and get the codes, even if "check engine" light is not on.... however a good tune up wont do any harm... (clean injectors, change all filters, sparkplugs and cables too, etc...)

let us know... good luck

 

got it all fixed... it was the mass air sensor..easy fix.. but still having problems with the4x4 engaging.. press on the switch and it dosent even light up.. (replaced it also) still nothing

 

4X4 issue is probably the shift motor on the back of the transfer case. These tend to crud up from non-use. Requires a security torx to remove. You can normally clean these up and re-install.