Just a bit more info on those AVCS bolts
There are 4 bolts in the system, 2 types.
Rear passenger head and front driver's head (behind the timing belt cover) have filters, they also have a small (1/8") bump in the center of the bolt head.
The bolts on top of the OCV are the same passenger vs driver, they have no filter, and the head of the bolt has no bump (it's flat).
That's a pretty easy way to see which bolt is which, you should have 2 bolts with a bump (on the heads), and 2 bolts without (on the OCV).
Is it possible your cam timing has jumped a tooth? I imagine that would throw a cam position CEL and probably disable, or at least cut back on the AVCS advance.