EGR trouble shooting
My 1994 Explorer Sport has just started having an issue wherein after warming up to normal operating temperature (either driving or idling) and being shut off, it either refuses to start until the motor cools down for a period of time (either minutes or hours) or it WILL start but will idle at about 300 RPM on the verge of dying. I read the trouble codes via a multimeter and found that the "EGR sensor voltage [is] out of range" and the "EGR circuit [is] higher than expected." My Haynes manual does say that the EGR valve isn't necessarily bad, but there may be other causes that would result in these trouble codes. Does anyone know if there is a common theme with the 1991-94 explorer EGR systems?