It's somewhat encouraging that it could just be yet another bad EGR valve... So for you, the cheap ebay one seems to be good (so far), but the Napa ones not so much. Of the 3 brands I went through, Delphi, Standard Motors, Evan-Fischer, none of them seemed to last any longer than the others. I do not know what the brand was on the original that lasted 10 years. Has anyone out there discovered an EGR that might be a bit more hardy than the others?