BMW E46 & E39 Most Common Vacuum Leaks P0171 & P0174
The
P0171 and P0174 codes will plague every owner of an
E46 or
E39 BMW at some
point in their lives. So, 99 times out of
100 they are caused by a vacuum leak and on the
M54/
M52 engine there are a few common causes of vacuum leaks. So common that I'd say 95% of cases will be covered by what
I go over in this video. I also talk about what a vacuum leak is, how a
MAF sensor works, and so on.
One thing I don't cover in this video is how to test your oxygen sensors to see if they are working. I will do that in a future video.
Please also take a look at these other videos
I've published:
E46
Common Repair Steps
https://youtu.be/Zt3XFkd97dc
E46
CCV Replace & Intake
Removal (Part 1) - See It Clearly!
https://youtu.be/ZDP8Dma0nUs
E46 CCV Replace & Intake Removal (Part 2) - Put It
Back Toge
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