Thanks adnoid! Printed your post and showing it to my mech. I'm keeping my fingers crossed.

Thanks Adnoid - I had the same mix of codes (p0171 p0174 p0300 p1342 p1345 p1347 p1348 p1350 p1352) and knew it wasn't the Y duct (replaced last year). I pulled out my DISA Adjuster Flap and it looked just like you your photos. :thumbup:

Code P0171/P0174/P1158/P1160
 

I was having those codes too until after, I discovered it was
caused by vacuum leak. (Smoke test revealed that intake manifold gasket needed to be replaced).
But right after when I finished, my X5 runs like crap with all the codes that you guys referred above:( Because of my mistake
(One of spark plug were left disconnected + the other two vacuum
lines that I mentioned below also left unplugged.

But thinks God I was taking pictures of my entire job while working @
the parking lot of one autozone near my house; Amazingly 3 days later,
I was taking a further look @ those pictures to determine what could have
done wrong for my car to be running even worst after replacing all this parts.
Than:woohoo:I discovered what went wrong: About 3 vacuum lines were left
disconnected including one spark plug as I mentioned above.
Now, my baby is back on track:thumbup:
So, you think you run smoother than me! I dont think so:nanana:

Great pic...hijacked and modified for selfish reasons. I consider myself to be a pretty good detective but I cannot find this friggin' part listed anywhere. Photo now points to the as of yet, :dunno: unidentified line...here's what I found by following. It comes off of the tube that the MAF connects to (see schematic pic)...runs back to the firewall turns toward the driver's side to inner apron where it disappears behind a mounting block while heading toward the pavement. I assume it has something to do with air since it comes off an intake tube. I am only beginning my journey to resolve my p0171 and P0174 and so I'm replacing any tubes that are "air" related. Mine cracked at the tip while investigating worthiness...I sure hope I don't have to remove the top engine components to replace...once someone tells me what it is :D.

Yeah! As you mentioned, this must be a selfish ignorant who have modified my work
pictures. However I completed that job inside of one autozone near my house which
was illegal to do so, but I have managed to do the job anyway and got back home
so tired to share everything I have done with other friends outhere, who also helped me
specially to complete such as heavy job like that. And...for someone to come, editing
or crossing a line on the instructions giving to follow the job properly, I think he's really
stupid selfish and probably one of the BMW's stealer outhere.

calm it , the dude is asking for help .
the diagram in this link suggests to me that hose is the brake booster vacuum
RealOEM.com * BMW E53 X5 4.4i Vacuum control - engine

mysweetx5...really?

Props on the effort...great instructions...great pics...even better that you did it at Autozone (illegally?)...hope that makes you feel better. I just wanted to draw the eyes of the person who would help me to look at the part I couldn't identify. You officially have my apology...in the interest of doing the right thing...I have removed your art.

Now go buy another make of car and join another forum b/c apparently the BMW community spirit hasn't moved you...

amacman...thank you for your support...you're right. I'm frantically trying to figure out what's going on with my car...I think this is the culprit. I did eventually find a part number. It's the vacuum pipe for the fuel pressure regulator. It's all chewed up on the end...and the car exhibits all the signs of this being the problem. Part number is 13 32 1 437 692. Car would at least run until this pipe came off...now it'll start but quickly dies after struggling to maintain 1000 rpms. Fingers crossed that this is the solution.
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Ok, here's the final on my P0171 and P0174 codes...

1. Replaced just about every vacuum related line I could find.
2. Cleaned the heck out of the MAF.

Car still ran rough but was at least running...then I noticed the smell of fuel. I backed the car out of garage for a test run and that's when it died (at the bottom of our steep driveway, of course). A Youtube video led me to believe I should test the fuel pressure...which was nada. No fuel in the fuel rail at all and the strong smell of fuel previously indicated to me that I needed replace the fuel pump and pressure regulator/filter. I took the back seat out and tested the pump. Once I established that it indeed was dead...I replaced it and the FPR. It was a cinch to do. Car's been running much better in terms of fuel economy and power. Been a couple weeks now and haven't had any codes return. If I had to do over again, I'd start with the fuel pressure check. Although I'm not feeling bad about replacing hoses that probably needed replacing in the near future anyway...the pressure check is extremely simple to do and you can quickly (and cheaply) confirm, or eliminate it as a suspect.

For the record, my X5 is a 2001 4.4i with 175k.

Hope this helps someone else somewhere down the road. :D

Do you ever clean yours with a designed MAF cleaner spray? My DISA is busted to heck. Ordered one that will be here Tuesday. Just wondering if its worth cleaning the MAF or not.