I have not seen a post where the MAF sensor has been cleaned or tested. Since MAF contributes to fuel mixture it can be the cause of lean codes and or pre cat O2 sensor faults.

I suggest cleaning the MAF thoroughly with MAF cleaner, easy to do and doesn't cost much. If you do so, be sure to spray all wires, liberally several times-- after you give the wires a good spraying you can tell where they are back to like new and where you haven't sprayed enough.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas