Thanks for this thread.

My Service Engine Soon light came on the other day.
I pulled codes = P0171 and P0174.
Searched this site, found this thread.
I've been waiting for an excuse to build a smoke machine, but figured I'd just do a quick visual inspection first.

I immediately noticed a ~1" long tear in the ~1" diameter hose of part 8 in the diagram above (BMW PN 13541440102). So I taped it up with electrical tape, reset the codes, and a new part is on order right now.

BTW, service records show that this exact part was replaced at the dealer 5 years and 26k miles ago. Is it possible for it to tear like that so soon? It actually makes me doubt the service records now - not that the PO was trying to trick me, but that he was constantly getting ripped off by the dealer.

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2001 X5 3.0i, 203k miles, AT, owned since 2014