What to do if your Ford Focus runs rough at idle?
What to do if your Ford Focus runs rough at idle? The fix is to seal the DPFE sensor so water cannot get in, but the way you do this will vary depending on whether the sensor is mounted on the firewall or is a tube-mounted DPFE. Remove the DPFE. Fold the insulation on the partition wall downward so it lays over the top of the EVR. How big is the insulation on a Ford Focus? Trace out a 2.5" wide x 3" tall rectangle in the insulation, starting from the bottom, and just outside of the EVR mounting lugs....