Wanted to change the EGR valve on my 1997 Sable 3.0L Vulcan but I did not have the proper wrench to loosen the nut that attaches the EGR tubing to the EGR valve.

Does anyone know what is the size of that nut and/or what is proper size of a wrench to loosen it?

I do not want to pay big bucks to the dealer if I can do it myself.

Looked all over but no one seems to know the nut size and/or the proper sized wrench to use.

Info is appreciated