I tried this again last night just for the sake of tinkering, I didn't even make it home from the shop before the SES light came on.
I put it back to stock and checked(and cleared) the code at work and sure enough, it was P0171. For some reason my car just does not like this mod, I tried it when Andy first posted it on here, and got the same code.
I just think it's odd that people have been running the VGS with no problems, and my car doesn't want anything to do with it. It's probably just as well, as the car felt kinda weird with it. Smoother, but weird.

Something else that's odd is that I used all caps in the title, but it posted with lower case.

 

Maybe it was a swear word! (Must be feeling pretty chipper today!).

Do you have an air/fuel ratio meter? What I have learned from helping a friend (Miata with Individual throttle body per cylinder) is that until you have a lot of experience, it's difficult to tell what is going on without gauges!