EGR valve

I have a question please,
I have a 99 E150 and the check engine light came on, I connected the scanner and the code it gave me was the EGR valve then I replaced it and erased the light and droved it for a week before the light came back on again I connected the scanner again and the same EGR code shows again, what else could I do, maybe the EGR valve came defective?
could you please give me some advise
thank you!

Ignacio;