How to Replace the DPFE Sensor on a Ford Escapeby Don Bowman
A DPFE (delta pressure feedback EGR) sensor on a Ford Escape is designed to sense the amount of EGR (exhaust gas recirculation) flow. The EGR is used to introduce burnt exhaust gases back into the engine through the intake manifold only at cruising speeds. This introduction of exhaust gases helps prevent pre-ignition by cooling the combustion temperatures, and it helps reduce emissions. A bad sensor will cause a stumble or rough engine at part throttle around 40 mph. And when the sensor begins to fail, the "Check engine" light will come on and show a code of "P0401," meaning that EGR flow is insufficient.
Remove the rubber hoses from the bottom of the DPFE sensor. The sensor is located on the firewall to the rear of the EGR valve. It is a black square box with an electrical connector plugged into the front. When the hoses are removed, inspect them for contamination. Oftentimes, the larger hose will filled with a white-looking powder caused from moisture. Use a small screwdriver or pick and break it loose and shake the powder out. If the hoses are too contaminated, remove them and clean them out.
Remove the electrical connector from the sensor. Remove the two screws holding the sensor to the firewall.
Bolt the new sensor to the firewall. Install the rubber hoses on the bottom of the sensor, and plug in the electrical connector.
Clear the codes to reset the "Check engine" light. Plug the code scanner in to the OBD connector, which is located under the driver's side dash. Turn the ignition key to the On position without starting the engine---just make sure that the lights on the instrument panel are on. The code scanner has a button labeled "Erase." Push this button and the scanner will display "Wait." When the scanner shows "Codes cleared," the check engine light should go out on the instrument panel. If the light did not go off, turn the ignition key off for a few seconds and start the car. The light should be off at this point.