DPFE = Differential Pressure Feedback EGR (this probably means nothing to you
)
It basically measures the pressure difference (hence Differential Pressure) between two sides of the pipe that goes from the exhaust to the EGR.
The DPFE is a rectangular (usually silver-colored) box that is located about a foot below the EGR valve. It is attached to the engine with two bolts. It has an electrical connector and two hoses attached.
One of the hoses must have come unplugged. I have heard that this can happen if the catalytic converter is plugged up and causing too much pressure.
Anyway, to get at it you will probably have to remove a few hoses (IAC hose and right-hand PCV tube probably).
