Increased emissions SES help?

[Porschefile]

Threw a code saying increased emissions and SES, with codes 2739, 27C5, and A8B6. I searched and saw some references to the secondary air pump, sensors, and so on, but no definitive fix. Anyone had the same issues fixed?

[TRS_Tom]

I've just gotten this "Increased Emissions!" warning... Haven't pulled any codes yet. Did you ever get it resolved?
My e92 M3 DCT has a crazy hesitation/sputter from a dead stop. If I accelerate softly it's fine, but if I tromp on it, it sounds like its choking on a hairball and then after 3 or 4 coughs it roars to life... So annoying.

[steven747]

maybe the fuel pressure sensor above the intake box. that's what the increased emissions was for me.

[jjandlj]

Reviving this a bit as I just went through the 2739 and 27C5 plus an occasional random other code issue. Codes would get set on first drive of the day after sitting for a week, but then I'd clear them and they wouldn't come back, even after sitting all day. Car was getting a little slower to start, and on my E39 540i6, when the battery started going flat the dash would start lighting up and it would start throwing codes. With that in mind, I started looking at the battery. Nocco Genius charger full cycle left it at 12.7V and it dropped to 12.4 overnight. Seemed like a big drop over less than 12 hours with no load. Repeated the next night with similar results. Replaced the battery this morning and all is well again. No codes. All I can figure (though I'm probably wrong) is the secondary air pump is a big load as soon as the car starts and may not have been spinning up soon enough to pass the built in test point. In any event, if you're getting these codes, you might check your battery.

[DrFerry]

The Differential Pressure sensor (it's below the brake servo booster) can also cause the Service Engine Soon (SES) light to code especially if the idle drops when your foot is on the brake pedal at red lights etc.
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[spammysammich]

Originally Posted by DrFerry

The Manifold Air Pressure sensor - MAP - (it's below the brake servo booster) can also cause the Service Engine Soon (SES) light to code especially of the idle drops when foot is on the brake pedal at red lights etc.

The MAP on this car is located in the idle strip for cylinders 5-8. You're probably thinking of the low pressure sensor for the brake vacuum assist.

https://www.fcpeuro.com/products/bmw...or-34302283605

[DrFerry]

Originally Posted by spammysammich

The MAP on this car is located in the idle strip for cylinders 5-8. You're probably thinking of the low pressure sensor for the brake vacuum assist.

https://www.fcpeuro.com/products/bmw...or-34302283605

Yep, you're exactly right. FCP Euro refers to it as the "Manifold Differential Pressure Sensor" and RealOEM just calls it the "Differential Pressure Sensor" (see image below) - though obviously it's nothing to with the rear axle Diff (LOL). Mine has almost 150K miles and is due for a change because now the idle drops from ~750RPM to about 575-600RPM when I press the brake pedal when stationary. There's various threads about the idle drop issue, but thanks for taking the time to point out the correct name for the sensor. I suppose either a bad MAP or a bad Differential Pressure Sensor can affect the idle drop issue? May the spam be with you.

Increased Emissions - Solved - Thread:
https://www.m3post.com/forums/showthread.php?t=310475
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