Come on!!...i know what is egr valve. You have a vaccum on your 87, that doest break!
History about "the piece of shit"
1- the gasket
ON the egr valve was leaking, impossible to change
2- the base was cracked(not at the installation but when the mother*** unstall it at junkward), another leak!
3- No more power on(check engine and tested)... :roll:
4- base was cracked once again !!
Now i'm very tired !! All of those are used at junkyard, for a new one its 500 CND box !
PS: GM wiring harness is the most complicated wiring i never seen !!