99 Taurus EGR Insufficient Recirculation

[kennewickman]

Have a 99 Taurus with 3.0 L Duratek engine. Service engine light came on with Code 401 - EGR recirc insufficient.

Have checked EGR valve with vacuum tester and it appears to operate correctly.
Have not figured out how to test the DPFE sensor while installed (it is fairly hard to remove/install). On the 3.0 L Duratek engine, it's buried deep in the bowels between the block and the firewall. You can barely see it or get a hand on it. I can feel the hoses and the wire connector but I can't see how to release the wire connector.

Have bench tested Solenoid valve and it seems to function correctly, but as designed (the orifice on the vacuum input is small) it seems incapable of providing enough vacuum to operate the EGR valve. I have tested it on the vehicle (Have ~ 15 inched input vac to the solenoid and less than 0.5 inches output vacuum with 12 volts to the solenoid) and no apparent movement of the EGR valve.

What I really think is that the problem is with the solenoid. However, I picked up 2 used solenoids from a Auto yard and all 3 operate similarly (i.e. they open and close when voltage is applied, but the orifice hole is so small it is not allowing significant vacuum to the EGR valve? Am I misunderstanding how this is supposed to work?

What am I missing?

[way2old]

Ford had a bad run of the DPFE sensors. 98% of the time the DPFE cures the P0401. They also will clog the ports with carbon. Good luck.