serialpyro

Hello. I am faced with a problem on my clk 200k which I do not get out of. I have an air flow on the maf that is far too low (fault p0101). The only solution that I found and which is surprising because it is downstream of the maf, is to disconnect the pipe between the maf and the exhaust recycling valve. But I can't ride like that because my compressed air is largely lost. I already spent a while taking out the kompressor to change all the breather hoses and the valve. The problem is still there. I had tested two new maf too.
Other question, does this valve (canister?) might be one way ? Thank you very much.