So interesting you said that. I looked it up and very first thing that I noted, was articles about faulty valve causing a gas smell inside the car. Which is exactly what I've been experiencing lately. How it burns your eyes a little bit and when I get moving it dissipates quickly. This was the article I stubbled across
http://www.themustangnews.com/conte...-odor-issue/nggallery/slideshow/#.W_RscuhKiM9
Just to verify, I resorted to my service manual and followed the diagram and sure nuff, its exactly what it is 'Purge Canister Valve'
But wait a min, that's for a 3.8 it says....... and I have a 5.0. But it clearly matches whats in the service manual. I traded the line and it connects to the vapor return tube on the canister. The line could be in better shape, little crackly and probably will replace it.
So if I look at the 5.0 diagram, it shows the Purge Canister Valve away from the firewall, on the passenger side fender apron with the charcoal canister towards the front bumper.
I'm wondering if this is one of Ford's wonder extras they threw in for free. As in the wiring harness is indeed for a V6, but the plug for the 5.0 was also supplied as part of the EGR vac harness. Kind of like how these cars are [OBD I] but they decided to include the [OBD II] port on it, even though its not connected to anything on the GT, but is on the V6