2012 528i Drivetrain malfunction after muffler swap

[sbain9395]

Hey so ive been getting a drivetrain malfunction on my screen after i swapped my stock 2012 528i muffler to a flowmaster super 10 series muffler
it only happens at high RPMS on comfort mode and high / low rpms on sport mode no check engine light but i do get the drivetrain malfunction warning on my screen
car goes into limp mode is it because theres not enough airflow or too much maybe? i might just get my old muffler welded back on to see if that fixes the problem.
has anyone else experienced this problem? or know what the hell is going on

Cause : https://imgur.com/gallery/sJ0msOo?fb...Oyzu3c2s0UMb24

[White94RX]

You already started a thread on the same exact topic. There were several responses in the thread advising you on how to proceed. Why are you starting a new thread?

[sbain9395]

they told me to scan for codes i scanned and got zero codes back no check engine light is on just a drivetrain malfunction error on screen and loss of power when the error comes on.
On another forum some are saying the new muffler couldve let the cat get clogged up maybe? also the stock muffler is tuned to that specific muffler allowing a certain amount of back pressure so the new one is messing with it? some saying its back firing im not sure im just gonna take it back and get the stock muffler put back on and see if it fixes the problem.

[White94RX]

If the drivetrain malfunction warning comes on, there are fault codes stored. That's a fact. You're probably not using the proper tool to read them.

And a muffler change will not do anything to clog up a cat. Swapping back to the stock muffler won't change a thing. Quit wasting time and money and take it to someone who knows that they're doing. It's not rocket science.

By the way, I am ASE and BMW master certified with 15 years of hands on experience exclusively with BMW. I know what the heck I'm talking about. The fact is that no one on any forum can tell you what is wrong with your car just from your story. Anyone that thinks they can is a fool. Get the codes read, from a real BMW scanner and report back. Otherwise, quit wasting our time.

[sbain9395]

Thanks for being blunt. lol i called and set up a appointment with a BMW Dealership for wednesday ill get back with a update

[f10_M550i]

Well.....

[White94RX]

Good for you. Keep us updated.

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[E38740iMD]

you can download the MHD APP and use the code scanner functionof it. its free and the cables is 20 bux

[Critter7r]

If the drivetrain malfunction warning comes on, there are fault codes stored. That's a fact. You're probably not using the proper tool to read them.

And a muffler change will not do anything to clog up a cat. Swapping back to the stock muffler won't change a thing. Quit wasting time and money and take it to someone who knows that they're doing. It's not rocket science.

By the way, I am ASE and BMW master certified with 15 years of hands on experience exclusively with BMW. I know what the heck I'm talking about. The fact is that no one on any forum can tell you what is wrong with your car just from your story. Anyone that thinks they can is a fool. Get the codes read, from a real BMW scanner and report back. Otherwise, quit wasting our time.

Easy, Tiger. I'll get you a Snickers.

Does the F10 have an electrical connection for the tailpipe flapper? Maybe the new muffler doesn't. Then, at higher throttle applications when the DME sends the signal to open the flap, there's nothing there to respond. BAM, powertrain malfunction.

[Stück]

By the way, I am ASE and BMW master certified with 15 years of hands on experience exclusively with BMW. I know what the heck I'm talking about. The fact is that no one on any forum can tell you what is wrong with your car just from your story. Anyone that thinks they can is a fool. Get the codes read, from a real BMW scanner and report back. Otherwise, quit wasting our time.

While I sincerely agree with this post because it is the reaction I have to most of this noise....

I speculate the MuFfLeR ShOp left the vacuum line your exhaust flap off since there is no place for it to go on the junk Flowmaster can, and as a result you have a major vacuum leak robbing the EPDW of adequate vacuum for boost control resultant in the PWG turbocharger failing to make sufficient boost to meet requested torque targets.

Just a theory based on many halfassed cars I've seen come through the shop with self inflicted issues, of course subject to a fault examination with a legitimate diagnostic platform like ISTA. Your Hazard Fraught pocket sCaNnEr need not apply.

[White94RX]

While I sincerely agree with this post because it is the reaction I have to most of this noise....

I speculate the MuFfLeR ShOp left the vacuum line your exhaust flap off since there is no place for it to go on the junk Flowmaster can, and as a result you have a major vacuum leak robbing the EPDW of adequate vacuum for boost control resultant in the PWG turbocharger failing to make sufficient boost to meet requested torque targets.

Just a theory based on many halfassed cars I've seen come through the shop with self inflicted issues, of course subject to a fault examination with a legitimate diagnostic platform like ISTA. Your Hazard Fraught pocket sCaNnEr need not apply.

That's something I hadn't thought of. But if the car is behaving normally at lower revs leads me to believe that the wastegates are operating some of the time. Hopefully the OP will update us soon.

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[White94RX]

Easy, Tiger. I'll get you a Snickers.

Does the F10 have an electrical connection for the tailpipe flapper? Maybe the new muffler doesn't. Then, at higher throttle applications when the DME sends the signal to open the flap, there's nothing there to respond. BAM, powertrain malfunction.

I don't think that's the case, but I could be wrong. I can't recall if the F10 has an electric flap or a vacuum flap. But I do know that the default position is flap open. I have seen cars come in with them unplugged. I guess to make the car louder at idle? It does store a fault code, but the one or two I saw didn't have any driveability concerns.

I guess I need to backtrack a little and say a muffler swap, when done properly, won't cause a check engine light. But that's assuming they would be smart enough to plug the vacuum line with a screw or golf tee. And that's assuming a lot from a muffler shop. Lol.

But it always goes back to stored diagnostic codes. They will always get you going in the right direction.

Still waiting on the OP...

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[E38740iMD]

i dont think the op will come back after reading some of these replies

but in in for answers

[Critter7r]

I don't think that's the case, but I could be wrong. I can't recall if the F10 has an electric flap or a vacuum flap. But I do know that the default position is flap open. I have seen cars come in with them unplugged. I guess to make the car louder at idle? It does store a fault code, but the one or two I saw didn't have any driveability concerns.

I guess I need to backtrack a little and say a muffler swap, when done properly, won't cause a check engine light. But that's assuming they would be smart enough to plug the vacuum line with a screw or golf tee. And that's assuming a lot from a muffler shop. Lol.

But it always goes back to stored diagnostic codes. They will always get you going in the right direction.

Still waiting on the OP...

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Oh yeah. So the signal to close would be at idle, and it would open at heavy throttle. So there goes my theory.

[White94RX]

My theory of a muffler change not causing a check engine light went out the window when I was reminded about the vacuum line being disconnected causing a vacuum leak, and affecting the wastegates solenoid.

That's what we're here for. To bounce ideas off of each other. We do it all day long at work, even when we know the cause and solution.

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[sbain9395]

[UPDATE] https://imgur.com/gallery/sJ0msOo?fb...Oyzu3c2s0UMb24

- - - Updated - - -

Good for you. Keep us updated.

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[UPDATE] https://imgur.com/gallery/sJ0msOo?fb...Oyzu3c2s0UMb24

[White94RX]

Haha, yep. So it was caused by the muffler. Or should a say the dumbass that replaced it and left the vacuum line open.

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