[tetsuo111]

Sharing for others who may experience this problem.

Last summer the idle after cold start suddenly became erratic and 'surged', bouncing back and forth between 1 - 1.5k RPM, especially when the brake was pressed. The SES also lit. There were three codes:

P2D16 - air mass meter signal
P2D0F - air mass meter signal
P2D5A - control motor torque limitation

I checked vacuum, cleaned the injectors, and cleaned the MAF several times with CRC. The problem remained.

I replaced the MAF with a new part. This solved the problem. The motor runs smooth as butter now, even immediately following cold starts.

I haven't reset the SES yet, so will report back afterwards if the codes return.

The new MAF looks different. Pic 1 is the bad sensor that was removed. The new part is OEM. It has a white plastic piece partially formed around the wire sensor. Makes me wonder if the white piece fell off into the intake manifold.....

OEM MAF:
https://www.ecstuning.com/BMW-E91-32...nsors/ES34413/

Pic 1:

[W37V]

your picture abs makes no sense to me. did it break? how would that be possible? mine is like one on the link.

[fravel]

OP, please reset your codes and report back. My car has been presenting with similar symptoms and codes for months and I have not been able to resolve it. Not to discourage you, but I have changed my MAF sensor.

EDIT: Your old MAF does look really weird.

[tetsuo111]

The MAF in the picture does look different from a new part.

This is how it looked when I removed it from the air box. I suspect that the white plastic part seen on new MAFs may have detached from mine, leaving the "nude" version seen above. Since installing a new sensor, the engine runs smoother than it ever has. Like silk.

I cleared DTC codes last night and started the motor. The SES light hasn't returned. Will update if this changes. I also need to check inside the TB hose and intake manifold for the missing plastic bit.

[roundle]

Any change to MPG?

[tetsuo111]

The install happened two days ago, Jan 3. So no data to report.

I drove to the mountains yesterday, one hour each way, and the mpg indicates higher than normal (~20mpg), but this is to be expected for highway driving.

The car runs extremely smooth now. I expect higher mpg. Will report back