SES on on 1995 Chevrolet Blazer

My Snapon scaner only go's back to 96. The code I am getting is P0401. I have changed the EGR vale and still have SES light. Any suggestions?

2 answers
I cgange the EGR vale the light came back ok after about 10 mi.
Everything you want to know and more about OBD code P0401: http://repairpal.com/OBD-Code-P0401