E46Fanatics - View Single Post - Another P0171 code...
View Single Post
Old 11-07-2012, 11:45 AM   #28
OEM ///Member
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 23,211
My Ride: 330CiC, M5, X5, E93
SAP vacuum hose should only cause lean problems on cold start for the first 90 seconds if it is broken. Also I think the later version 330 did not have vacuum controlled SAP, these actually have a MAF for to measure the SAP airflow, you can tell because the hose from the SAP pump to the check valve does not have standard hose clamps, it has plastic quick release type clamps.

You also need to to check the vacuum hose at the fuel filter for the fuel pressure regulator as this breaks quite often as well.

Do not get overly excited about your O2 sensors at this point, might be wise to replace them, but they will do nothing for your overall lean condition, they just may react faster and be more active.

Fuel trims are heading in the right direction. You still may have a few issues to sort out with crankcase air leaks, valve cover gasket, oil fill cap, dipstick O-ring at block DISA O-ring or others. I usually prefer to see my fuel trims in the +2% or lower range, even long term.

You may also want to replace your fuel filter and check the 2nd link below in my signature for fuel pump issues.
Solve your misfires, lean codes, rough idle - http://forum.e46fanatics.com/showthread.php?t=897616

Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

Temp Info - http://forum.e46fanatics.com/showthread.php?t=964491

Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

E46/E39 GM5 Door Lock Info - www.bmwgm5.com

Lower hose temp switch O-ring - BMW #13621743299

Last edited by jfoj; 11-07-2012 at 11:46 AM.
jfoj is online now   Reply With Quote