Ford Explorer: Jim Warman - what is a DPFE sensor?

> I had the yellow "Service Engine Soon" warning light come on (2002 EB,
4.0L 

Make that "Less than". DUH.
 

I found some stuff on the internet about this. Does this sensor really fail
as often as people in some forums seem to say it does?

Differential Pressure Feedback Egr sensor..... Looking the the tube that
runs from the exhaust manifold, you'll notice the two hoses for the DPFE.
Between the two hose nipples is a "waist" or restriction. The DPFE reads the
difference in exhaust gas pressure between the two sides of the restriction.
The PCM uses this pressure differential to compute how much exhaust is
flowing through the EGR valve. The PCM will vary the duty cycle of the EVRV
(EGR Vacuum Regulator Valve) to control the opening of the EGR valve to
achieve the preprogrammed 'desired flow'.

These sensors live in a very harsh environment and it is not uncommon to see
them go south although the sensors on the 4.6, 5.4 and 6.8 don't seem to be
quite so troublesome.

HTH.

Jim Warman
net

Jim,

Thanks again. As always, you're the best.