Ford Repair: deiseling noise, mass air flow sensor, mass air flow

Question
my 2001 ford windstar limited with 91,ooo miles is making a deiseling noise at times while driving. I havent done anything yet because it doesnt happen all the time, it is my wifes car and i drove it about a week ago and noticed it for the first time.

Answer
make sure air filter is clean-look for vacuum leaks-pull mass air flow sensor out of breather housing-carefully clean two small wires in it with maf cleaner (brake cleaner works fine also)
if you break one of these wires it is ruined-if all this is good pull upper plenum replace upper and lower seals-unclog egr ports next to runners you will know what i am talking about once you get upper plenum removed-torque bolts back to specs so you don't break your plenum.