you don't have a mass air flow sensor,you have a manifold absolute pressure sensor in the intake.i'm not sure on it though.if you do have an maf it'll be on the plastic intake tubes close to the airbox.
Whitey Is right. There is no Mass Air flow sensor in these trucks. There's a MAP (Manifold Absoloute Pressure) Oxygen, And even An IAC (Idle Air Contol motor) But not Mass air flow. If you're having a problem with the way it's running, post your symptoms and we'll do our best