2008 Mini Cooper S: I was getting the Mass Air Sensor Plausibility error code for several months. Code 2b5c. I could clear the code, sometimes it would be a several days before it came back, sometimes quicker. This intake hose must have been cracked for a while. I finally totally broke it when taking it off. I used non-adhesive silicone wrap (about 1" wide) from the auto parts store. Since the crack would pull air into the hose, exterior wrap works. It's fixed. No codes. Runs properly.

Sorry if this is a repetitive post. I hope it helps somebody.

 

Had to replace A variable valve timing solenoid on my son's mini. To get to it I had to remove the hose for the air intake. I had put it back on but apparently not snug enough. Ran great for a week today he called me freaking out bc of CEL and car acting odd. Ran code scanner on it, looked it up, once I found this thread went out there and sure enough, the bottom side of the hose had shimmied off. Put it back on "snug this time" and voila. Thanks for the tip!

 

2009 JCW Clubman.
Have had this code repeatedly and this
cracked hose at turbo inlet.
Replaced the hose but code keeps
coming back.
Replaced MAF sensor but code keeps
coming back.
Will replace throttle body this weekend
because I have a VDO one coming in
tomorrow and maybe I could have stressed
the cheap plastic TB removing the
noisemaker before all this started.
Can’t find any other cracks or leaks but
that’ll be the next thing to check out more
rigorously. After that will take off the
intake manifold and check out the intake
valves for gunk and carbon. Don’t think
it’s that yet at only 43K with seafoam intake
treatments every 5K before oil changes
but maybe. After that if it’s still throwing
the 2B5c (p115c) code I’ll be stumped.

Hopefully it’s just the throttle body.

 

More curbside repairs at home
New MAF the other day
Didn’t fix 2B5C (P115C) code
Today: New throttle body and also
removed intake and looked at the intake
valves.
They had a layer of black crusty stuff
but not too bad so I hit them directly
with some Seafoam spray and a compact
toothbrush then some canned air 2 intakes
at at time, turning the crank in between
so I was working on closed valves.
All back together now, Seafoam smoked
out, and the code isn’t coming back
whereas it was happening every time
I drove the car before.
It’s nice when things go right.
Yay!!!