Oxygen sensor
The Manifold absolute pressure monitors intake manifold pressure and ambient barometric pressure. The PCM/ power train control module uses this input signal to determine engine load and adjusts fuel injection duration accordingly.
Inside the upper intake manifold, attached to the fuel injection spider.
It is under the intake manifold.
The fuel pressure regulator is located under the upper intake manifold and is attached to the injection "spider". The upper intake manifold must be removed to gain access to the regulator.
The injection rate is the number of injections. The injection pressure is the pressure the injection is under.
It's part of the fuel injection assembly inside the upper manifold.
This engine should be CFI (central fuel injection) and the fuel pressure regulator would be under the upper intake manifold, attached to the "spider" (bank of injector poppets). The upper intake manifold needs to be removed to gain access.
The vantage meter, sold by Snap-On is used for numerous automotive diagnostics. The transducer package is used for pressure measurements. (Fuel pressure, oil pressure, combustion chamber compression, manifold vacuum, etc.)
You need a chart which identified the relationship between the ambient air temperature and the pressure, as well as a manifold gauge set.
The Abbreviation for Manifold Absolute pressure is MAP.
If your engine is a 4.3L V-6 with CPI (central point injection) it is inside the upper intake manifold. The upper intake manifold is bolted on top of the normal intake manifold. The throttle body is mounted on it and your fuel lines terminate into the center of this.
If that vehicle is TBI (throttle body injection) it could be a faulty map (manifold absolute pressure) sensor.