Hi, 2004 BMW X5. Check engine light came on intermittently, now on all the time. Tested all 4 oxygen sensors and they are putting out within specs. Mass air sensor also within specs for output. Next step was to check fuel pressure. Suspected fuel filter had never been changed. Put new filter in and fault remains. Car runs great. Any suggestions to get rid of the fault light?

Thanks.

Hello delmundo, I solved my own problem with some "free" help from the bmw dealer. Found out my car has an warranty for 70,000 mi for emission related failures. Turns out in the absence of any vacuum leak that would add air to the intake manifold after the mass air sensor and cause the lean condition, the sensor had to be bad. The bmw dealer replaced it under the warranty and I am a happy bmw owner.