Has anyone had a CEL P0016?

[zumbi6]

My '06 6S MT has thrown this code a couple of months now. I had the local shop check it out. They changed both the camshaft sensors twice and the code came back each time after driving a mile or so on the street. The car revs and drives fine on the street and highway. The friggin' light is annoying as hell. I just have an AEM intake and RB exhausts which shouldn't have anything to do with this. I haven't pushed it too hard since the CEL came on.

Any suggestions would be greatly appreciated!