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Error code P0491 and P0171

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Hello Everyone,
So I'm having this issue with makes my check engine to light up every now and then outputting this error code P0491 and P0171 which to my understanding is related to the secondary air injection system on bank 1(whatever it means, I guess cylinder and system too lean bank 1.
So far i visually inspected the rest of the hoses around the engine but I didn't see any noticeable cracks on them.
I searched the around for this problem, but all I could find was information regarding a problem with the secondary air pump, which is not the cause in my case, because as far as I'm aware, the pre-facelift w204 models don't need that pump, but instead, the supercharger itself is doing the work, therefore, there is no secondary air injection pump. I'm wondering if this could somehow be related to a bad/clogged EGR valve too? Should I try removing it and cleaning it first before digging deeper into the system, or it has nothing to do with it?
I wasn't able to find any information on the internet regarding the whole air injection system, and all of the components, what I could find are simply little bits and peaces here and there, but nothing specific that could give me a better understanding of the whole situation.
I asked around, friends and different mechanics regarding this, but nobody really knows how to deal with it, but instead I'm getting a "if it runs alright, why would you care, just drive it like that" but that's far from a solution, which I'm after.
Any help on that matter will be appreciated....

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