opinions please!!

I recently started having problems with my 2000 ranger it is hard starting runs rich idles erratically and ocasionally tries to die on me ive done a tune up, replaced my oil, filters, plugs, O2 sensors, tps, even my thermostat becuz of a coolant leak havent found leak yet but it doesnt appear to be getting into my oil ( not milky ) and she only smokes when you first crank her up after she warms up she seems to run fine except at an idle after replacing each of the above parts she ran great for a day or 2 but has since started acting up again and the only thing else i can think of is either my eec or egr but would love any other possible opinions before i go back under the hood

I'd try cleaning the MAF sensor. It's located on the airbox. Just take it off and spray some carb cleaner (that says it's safe for efi sensors) into the hole where the small wires are. Try not to blast the wires with a stright stream though, just kind of mist them, then let it dry for a minute and put it back together. Worth a try!

Sounds like you spent a lot of money and effort replacing parts in the hope that it would correct the problem. Did you get any check engine light (CEL) at all? You must have. If you did, what were the codes?

Don't forget about a partially stopped up exhaust.