Hey steve.. I finally got the EGR valve off the Blazer... what a PITA!
Had to take off the Air warmer/filter assembly and use a LONG skinny 1/4" socket extension from the fan to reach the bolts... what a wonderful place Chevy picked to put the serpentine belt tensioner!
I had to sort of reverse your instructions because the plug wouldn't come off until the valve was unbolted and turned a bit so the belt tensioner wasn't pressing the plug on..
Anyway, I cleaned the pintle and seat, now I'm trying to find a Kleen Screen gasket for it.. (part #2-1357 at Tomco)
I've called all the easy ones... Napa, pep boys, kragen, Auto Zone, etc. with no luck..
Do you remember where you bought yours?
Thanks again for all your help!
Mac