Hi,

I tested my DPFE using the following method (adapted from http://www.ford-trucks.com/forums/34...fe-sensor.html)...

1. Remove the 2 rubber hoses from the bottom of the sensor.
2. Attach a piece of rubber hose to the forward most hole in the sensor.
3. The top wire is the active feedback signal wire. It will vary from 0-5 volts or so.
4. Either turn the key until the accessories are on or start the engine, either way is fine.
5. Apply suction to the hose and you will see the voltage change.
6. Do the same thing to the rear port but the voltage difference will be much less.

… my results from the forward port: voltage went from .9 volts to 5 volts
… my results from rear the port: voltage went down slightly with vacuum

Can anyone tell me if the results from the rear port indicate the DPFE is bad? (I know the forward port result is normal).

Thanks!