Engine Sensor Confusion

[earli]

OK,,, I've read a bunch of posts about fuel economy and check engine lights. On these posts I've seen EGR valve, Differential Pressure Feedback Sensor (DPFE) & O2 sensors. In the Haynes manual, the only sensors I can find are; Variable Reluctance Sensor, Air Bypass Valve, Air Charge Temp Sensor, Crank Shaft Timing Sensor. I have looked for these parts on Wrenchead.com and other internet auto parts sites. The only parts I can find are the Air Charge Temp Sensor, the Crankshaft Sensor and the O2 sensor.
Which of these are the same???? ie, is the DPFE the same as the Barametric Pressure sensor is the same as the Variable Reluctance Sensor?
I'd appreciate any help in clarifying this for me.