Owners have issues with these,hence the post.As with all things Ford, the design has changed from the early and later Contour days. The DPFE sensor was introduced by Ford when OBD II came in , to monitor emission components, in this case, the operation of the egr and to check it is working by checking the flow thru the egr tube.The DPFE sensor is a mini barometer..there is no flow thru the hoses.The EGR tube has an internal restriction /venturi between each hose connection..This pressure differential ,caused by flow,is what the DPFE check..no differential pressures then no flow and MIL light comes on. These sensors have had many issue...water in tubes due to hot/cold causing condensation and sensor failure, hoses burning up due to heat of egr tube.The design of the sensor and its tubes has been changed over the years. The latest type of tubes are thicker wall and have an Si inner core to help resist the heat.If you have issue with these be sure you replace with the latest genuine Ford parts..and NO any old tube WON'T DO..this is a 'hostile' area so use the latest ,correct parts. the pics(sorry for quality) are of the current Focus DPFE tubes, smaller length but you get the idea with the thicker wall and the Si (red) core to resist heat.Owners of T/C cars that retain EGR and still have the egr tube on the exhaust manifold should consider a mod to relocate the EGR tapping on the turbo 'out' side of the system...this operates at lower pressure than the pressure build up between the exhaust manifolds and tubo turbine 'in' side...Don't forget, as boost goes up from the compressor side of the T/C so does the pressure on the turbine (exhaust) side of the T/C..it has to get the energy from somewhere!..The DPFE sensors do not like high pressures in the exhaust manifold...

 dpfe_tube1.JPG ( 506.27K ) Number of downloads: 22
 dpfe_tube2.JPG ( 436.01K ) Number of downloads: 20


... T/C owners can always add a 'T' to the DPFE hose nearest the exhaust feed , to a pressure gauge and see how increases in boost also increase exhaust manifold back pressure....on high boost the tubes can blow off...

The larger DPFE tube pops off for me every time. I am running 8 psi. I have clamped the hose down, but I fear 1) the clamp is not tight enough and 2) tightening the clamp further will cut into the hose. Good to know about the upgraded hoses.

Terry, what do you mean by "the DPFE sensors do not like high pressures..." In what ways to the sensors express their dislike?

I think in a nutshell Terry is referring to all the people (with turbo conversions) who route the EGR feed from before the turbo and not after the turbo. There is no backpressure after the turbo, which is where the EGR tube should be placed - Not before where backpressure is needed to get the turbo spooled (which consequently blows the DPFE tubes off). Apparently designing a turbo system properly means thinking about how the other systems interact in the engine compartment (and not just how to fit it and how much boost it produces).

-Dom

...the dpfe sensor measures small pressure changes across the egr tube venturi...when exhaust gas flows at normal exhaust pressures.It is a 'dead head' sensor..up the pressure and the sensor was not designed to take such exhaust back pressure that comes with a t/c in the system..The early units will fai and later plastic units..due to excessive pressures...will no longer dead head and once you have 'flow' to the dpfe it will burn up a plastic (later) unit....