1995 Legacy L EGR Humming noise

I just recently picked up a 1995 Legacy L Wagon with 127,000 miles as a project car. The car needed brakes lines and was having issues with starting. Since then I have replaced the spark plugs, spark plug wires, crankshaft sensor, camshaft sensor, and pcv valve and the car starts everytime and is running a lot better. The only thing I noticed is that the EGR makes a suttle humming sound even when the car is off and the key is out of the ignition. Is this anything I should worry about?

i don't think it is the EGR. i have never heard of that. but i guess it could be.
but it could be the ABS pump / control up by the right head light.
there is /was a recall i think on those for running after the car shut off.
the replacement part has a different part number with an ''R'' on the end i think.
see if that is what is making the noise.