5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
2002 bmw e39 525i p0171 p0174 sytem too lean bank1 bank 2 help?
Hi aim going pretty much crazy with my 2002 BMW e39 525i with 78k miles i have been getting these codes p0171 , p0174 system too lean bank 1 bank 2.
I have done pretty much everything and spent hundreds on dealers and repair shops any help would be highly appreciated i have done the fallowing repairs >
1.replaced all 4 oxygen sensors Bosch brand.
2.replaced air cleaner box.
3.replaced both air boots.
4.replaced ccv valve.
5.clean maf sensor.
6.used seafoam cleaner
7.car seems to run fine engine idles good not rough i always us highest gas so any ideas on what to do would be highly appriciated thanks
I already changed both air intake elbows and i don't hear any engine noise and all the air hoses seem to be fine i think because i sprayed the air intake and most hoses with carb cleaner and didn't noticed any difference on the idle any help and suggestions would be thank full
Rely on mac in the trade thats what i've been told feel like quite a retard
feul filter needs changeing but have not found one for this car yet it has 4 connection and the one that show in the book are only two thanks again for all your help
My 98 540i was throwing the same codes. It was my throttle body gasket. About $10. Spray some throttle body cleaner around the gasket area while the car is idling. If it starts to speed up then you know that's the problem. Mine wanted to die instantly. The icv (ignition control valve, only on 97 & 98's) was completely gummed up. Changed gaskets and cleaned out the icv w/ WD40 and it runs perfect now. I'm going to do this to my 98 740iL next week as preventative maintenance (206K miles).
Good luck, hope this helps!
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.