Location of Oil Control Valve (OCV) Filter

Hi Everyone. Need a little help with a 2006 Tundra DC Ltd (4.7L). Is the OCV filter on the 4.7 litre engine integrated into the valve or is it separate?

Background: I replaced one OCV a few months ago to resolve code P0022 (all codes were erased afterward). No further codes until recently when both P0022 and P0012 came up (sorry, can't remember which was in "Stored" and which was in "Pending"). The new OCV tested fine so went ahead and changed the other OCV (in case it was failing intermittently) and cleared the codes. Code P0022 returned a couple days later, but not P0012. I was told that the OCV filters were integrated into each valve. Is that true? I see the filters can be purchased separately but darned if I can find where they are located on the engine. All troubleshooting suggestions and guidance is much appreciated!

P.S. - The truck currently has 105,000 miles and the timing belt was replaced about 20,000 miles ago.

Cheers!