I believe the DPFE sensor is at the back of the 5.0 L by the throttle body
On the 4.0 L - OHV - engine , its on the drivers side of the upper " plastic " intake manifold
I'm not a mechanic / technician but I had the DPFE sensor changed on my Ford Explorer . As far as I know it is used to control the amount the Exhaust Gas Recirculation ( EGR ) valve opens
On my 1995 Ford Explorer with the 4.0 liter OHV engine the DPFE sensor ( differential / or delta pressure feedback Egr sensor ) is located on the upper intake manifold on the drivers side of the engine
you needs a dpfe sensor
On the right rear of the engine by the throttle body.
The delta pressure feed back egr sensor is located on the intake manifold. It is a metallic rectangular thingy with vacuum lines and a connector on it.
The DPFE is located on the left side of the upper intake manifold across from the battery. It has two rubber hoses on the bottom with a wire connector attached.
Ford is the only American car company that uses a DPFE sensor. GM dpfe sensor are built into the EGR.
I dont believe the Impala 2003 uses a DPFE sensor as part of there Emissions system.
P1401 is DPFE sensor circuit high, check out this tutorial to replace the sensor on your Ford
YES - www.motorcraft.com lists a DPFE sensor for all available engines on a 1996 Ford Ranger