my explorer is idling rough and has no power?????help

[Yazgar]

Hello all my name is Yazgar, I have just taken over my sons 1994 explorer, when i took it it ran rough but started and was drivable, the exhaust was broke off just after the catalitic converter so I took it to the shop and they put pipe and muffler on it, within two days it started running so bad I could not get any power, the whole truck shakes when idleing in gear, really bad when cold start wont stay running, actually my first ford so wanna get it goin and make it a good change not a pain in my side. thinkin several things might be cause.....fuel injector, but never had one go out and act like this....tune-up! just wishful thinking cause thats the easiest fix, lol....clogged converter (expensive)....timing belt (even more expensive)....mass air flow sensor (they can make a car act crazy), well, does this sound familiar to anyone?
; any suggestions?

 

[BackBone]

Could be any one thing or a combination of ailments. Have you tried checking: Fuel filter, Air filter, Plugs, Cap and rotor? May have a vacuum leak. Usually you can check for a clogged cat by using a vacuum guage. At idle, you should have steady vaccuum (cant remember what) but if you rev it, your vacuum should drop down to zero and them climb back up. With a clogged cat, vacuum usually will stay very low during this test. I would recommend taking it to a mechanic to do the test if you are not familiar with diagnosing engine problems.