2001 BMW X5 lean mixture fault codes

2001 BMW X5
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CCHANDONNAIT
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2001 BMW X5 6 cyl All Wheel Drive 71000 miles

I keep getting a lean mixture fault code that activiates the service engine light. I clear the code but it will come back on within 24 hours. The air intake boot was recently replaced. What else could it be. Thanks
Feb 17, 2009 at 5:30 AM
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RASMATAZ
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A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)
Feb 17, 2009 at 5:54 AM
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JBZNUPE7
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Try the o2 sensors. That is what was wrong with mine.
Mar 21, 2009 at 3:09 AM
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DOCHAGERTY
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You have reset the fault but when you repaired the intake boot, did you reset adaptations?
Mar 21, 2009 at 11:58 AM