Why is my car different?

[Bowline5]

I have a 57 plate Forester XTE 2.5l turbo with a recurring CEL fault in the secondary air system. I've spent a lot of time on the 'net learning about the system, when I set about checking the circuitry to find I do not have the wiring and components that all the forums and diagrams say I should. There is no Aircut2 relay in the box that should operate the left hand valve, the carrier is there but no wiring in it. Can this mean I only have the right hand valve? Surely not. The CEL fault is intermittent, I can clear it with the OBD scanner and a couple of days later it comes back. Sometimes the scanner reports no fault but if I choose the Clear Codes option it goes through the motions and the CEL stays off. What I am sure of is that the air pump itself is working, hence the deep dive to find the problem. All this faff just to fool an emissions tester once a year!

Any advice or suggestions please.