[ednyc2nc]

need help!!! my service light is on I get a code read P0174 vacuum leak!!! What have you guys found to be the problem when you got this code ???

[Corno_Baldwin]

P0174 means system is too lean. I.e. Too much air/not enough fuel - it could be related to vacuum but doesn't necessarily mean there is a vacuum leak.

-Inspect all vacuum hoses
-in tank fuel pump putting out ok pressure? This pump is also referred to as Low Pressure Fuel Pump (LPFP)
-is High Pressure Fuel Pump (HPFP) putting out correct pressure?
-check all intake pipes
-possibly check exhaust connections - specifically down pipe? Just not sure if enough air could get sucked in there to say the mixture is lean - just a thought.
-injector issues not allowing enough fuel into cylinder

Sometimes you can visually spot issues with the intake piping and/or vacuum lines - other times you have to smoke the system to find leaks. As for fuel pressures, I know INPA shows pressure and I believe the Carly app does too (just the scanners/software I have used). They recently did an update and some parameter names have changed and it was harder for me to figure it out last time. It would also be good to find out if any BMW specific codes are stored, especially those pertaining to the P code you have. Bavarian Technic, Schwaben, Carly to name a few - or load up INPA. Having the generic P codes and the BMW codes together can be quite helpful at times in diagnostics.

[ednyc2nc]

thanks for the info !!!