EGR Valve
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Mercury Sable, 2002 Mercury Mountaineer, 2002 Mercury Grand Marquis, 2002 Mercury Cougar, and 2002 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
EGR valve in the DPFE EGR system is a conventional, vacuum actuated EGR valve. The valve increases or decreases flow of exhaust gas recirculation. As vacuum applied to EGR valve diaphragm overcomes spring force, valve begins to open. As vacuum signal weakens, at 1.6 in. Hg (5.4 kPa) or less, spring force closes valve. EGR valve is fully open at about 4.5 in. Hg (15 kPa). Since EGR flow requirement varies greatly, providing service specifications on flow rate is impractical. The OBD-II system monitors EGR valve function and triggers a DTC if test criteria is not met. EGR valve flow rate is not measured directly as part of field diagnostic procedures.