Service Engine Light - Code P1175
Trying to get ideas of what might be wrong with my car. 2000 540i/6 with ~126k miles. Short story is my check engine light came on. Took it to the local auto place and the code came up as P1175 (fuel trim adaptation additive bank 2 malfunction. Explanation: large vacuum leak on engine).
What's happening is for the first few minutes after a cold start my idle is pretty rough. Every once in a while when the car is moving and I take out out of gear and don't have the clutch pressed the revs will drop to 0 and the engine will die. The problems go away as soon as the temperature gets to the normal running temp.
I have searched around and everything I have found shows that P1175 is accompanied by P1174. I have yet to find anything that shows only P1175 being thrown, which is my case. From reading around it seems it could be anything from the MAF sensor to gaskets/o2 sensors.
I recently replaced the alternator (for the second time, first replacement alternator went bad) a week ago or so and am wondering if the vacuum leak could have been caused by anything I may have taken off and not put back properly (specifically the air filter housing). My dad also decided he wanted to clean my MAF sensor just before I did the alternator. I am curious as to if there is the possibility of that being cleaned or re-installed improperly which could be causing the problem.
tl;dr - CEL throwing code P1175 only. Any help or ideas would be greatly appreciated. Thanks!
Last edited by necero; 01-17-2013 at 08:50 AM.