91 Taurus Check Engine Light

[ZANDDATTACK]

Hello there,
3.0 with 173,000

Check engine light comes on consistently now upon reaching full temperature. I pulled the codes with the following results,
332 and 337 EGR opening not detected and EGR sensor incorrect voltage

With the engine idling I pulled a suction of 8 inches directly on the EGR valve and the RPM dropped about 75 and upon removal of the vacuum the RPM returned as before. Next, I hooked up a vacuum gage in series with the EGR valve and I rigged it so that I could view the gage while driving and this is what I saw, there was no vacuum at idle and during light acceleration I saw about 5 inches. When I backed off on the throttle the vacuum went to zero. At this point I believe the EGR system is putting the correct amount of exhaust gases, at the correct times, back into the engine.

Just a note also that the car exhibits very little detonation and no driveability issues.

Next, I inspected the EGR sensor and saw no obvious problems.

My questions are, have I missed anything in checking the EGR system and does anyone know the test specifications for the sensor? I would really like to test this sensor before replacing it but can't find any info.
I thank all that respond.
Steve