EGR Valve???

Hi my son-in laws 1996 taurus would not pass emissions because of system readiness ,we checked with a monitor and found egr reads never ready even after going through drive cycles many times ,we have checked vacuum switch and delta modulator,and vacuum checked egr valve and all have been satisfactory . I'm stumped

With no codes and if only one monitor not ready should be able to pass emission with no problem as 1996 to 2000 you are allowed to have two system monitors not ready
2001 and to date only one