One thing to keep in mind about many codes is that the ECM will require a certain number of reps to occur or time to elapse, before setting the code and turning on the MIL. So it's very possible the pending code is being set repeatedly, whenever the lean condition occurs at that specific RPM. However, because the MIL is not on, you're not aware that's happening. And the pending code doesn't become an actual code, because the lean condition goes away when the RPMs change, and the computer can then erase the pending code from memory. One would think there should be code to recognize the repeating problem condition, but it's also easy to understand how the engineers can't program for every possible issue that might come up.
So I think the answer to your question is very likely yes. Hopefully it won't be too difficult to locate the source of the unmetered air, now that you know what you're looking for.
2011 3i 2.0 A/T 145K miles