I have a 02 sport trac and had the upstream O2 sensor replaced, PCV replaced and cleaned the MAF. upon doing these it runs fine for about ten min and sounds likes going to stall and shakes real bad. nod codes have come up yet sense I replaced those parts but my gas mileage is horrible. As the rough idle starts if I rev the engine it goes back to normal for about ten min and yet again sounds like it's going to stall but doesnt and shakes real bad, any suggestions?

 

Have you checked/cleaned the Idle Air Controller? Have your plugs/wires ever been replaced?

 

After I cleaned the MAF senor in my car, andit ran great for a day then decided to run bad. I cleaned out the throttle body and was good to go.