P0171 BMW - Mixture Control System Too Lean

Tech notes

If the P0171 is combined with the P0174 code, it's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replaced the air filter and clean the air flow meter. If the problem persist the front oxygen (O2) sensor may need to be replaced.


Read more: http://engine-codes.com/p0171_bmw.html  


願意探究細節的話，可以看看這兒：

轉自BMW X5論壇的一篇同類問題：http://www.bimmerfest.com/forums/showthread.php?t=471632