Limp Mode Increased Emisson

[TurooM3]

Hello there this is my first time posting on Bimmerpost i currently own a 2010 bmw m3 I bought the car April this year with 86k miles on it recently the car has been acting wired. First time I took the car downtown to time square it drive perfect didn’t notice anything off with the car as I come back home car gose into limp mode I check the status of the vehicle and it shows Engine malfunction and increased emission right away I pulled over and turned the car off. When I turn the car back on I notice that its still in limp mode and now I have a service engine light on the worst that can ever happen to a bmw owner very bad feeling but okay I drove the car back home in limp once I’m able to stop again I turn it off and turn it back on I notice now that the car is no longer in limp mode anymore and it’s not showing increased emission light anymore very wired if you ask me I really didn’t know what to do so the next day I take the car to my local shop that deals with bmw (The Stance Shop) Queens New York. My
Mechanic gose ahead and connectes his computer when the computer is done reading we both notice that there are no stored codes for some reason he check everything making sure everything looks and feels perfect. At that timeI had just got the car so I was driving the car more often just to make sure there was nothing wrong with it I drove the car about 150 miles and no errors came up everything was perfect . Fast track 3 weeks later beginning of may I go one day to my parking lot after the car been sitting for about 5 days I turn the car on and bang limp mode and increased emission back on so I drove the car to get the code read and I got a P2527 Code which is Vacuum Reservoir Pressure Sensor Circuit like I said I have never seen this before in my life. I asked around and people keep telling me to smoke the car and see if it has any leaks someone else told me it can be my throttle actuators that can be going bad on me I’ve also heard about brake poster senor or Evap senor or valve or the Vaccum pump it’s self can be bad. Recently the car has gotten worst gose into limp mode after 5 miles of driving it sometimes I’ll start it and out the blue the car would just turn off cut all power the the engine dose not give me a hard time start it back up. If anyone has ever seen this before it would be good to get some advice on what to do or what to check in the car. Currently the car has full Armytrix exhaust not sure if that can be the issue to plz if anyone can help thank you 🙏🙏

[Redd]

Did you change your brake fluid recently? Do you hear a frequent buzzing sound from your left side a-pillar? If yes then you probably have a damaged brake vacuum pressure sensor. These get damaged easily when brake fluid drips on it during a fluid change if the mech is not careful.

Also I think P2527 is a generic OBD2 code. You should find a mech who can pull BMW specific codes as they are much easier to troubleshoot.

[TurooM3]

Hey thank you for the response back I really appreciate it. I haven’t check that part yet Monday day the car is going to the shop to get checked out it’s funny that you say brake fluid cause I just noticed that the computer on the car is reading the brake fluid is over due and also would the car feel wired while braking if this is the issue ? When it brakes it dose not feel like it smooth brake for some reason feel like when I engage the brake it stops the car like if I’m slamming on it just things that i have noticed

[pjk380]

Not sure if related but double check battery voltage. If the battery is not in good shape these cars can throw out all kinds of weird error codes. Resting voltage should be 12.5V-12.6V and around 14.0V with engine running.

[spammysammich]

Brake service interval warning will not make the brakes feel weird. Abnormal brake fluid levels or air in the lines will. Check your alternator and battery’s health, get a brake service done. Report back.

[DirtyThreeSix]

Had a very similar issue. After i replaced my brakes that same sensor went bad due to a bit of brake fluid going on it. Sensor sometimes wouldn't put it in limp mode, but after driving a bit it'd come on. Replacing the sensor fixed my issue. Hope this helps.

Update: Car would also read no codes unless it's actively on limp mode due to the sensor