What is the flap inside the left exhaust pipe?

justanotherx3 · 04-04-2020, 05:17 PM

I have a 2019 X3 30i, and noticed that the left tail pipe has a flap about half a foot inside. I don't see on on the right tail pipe.

Thoughts on what this is?

satz · 04-04-2020, 06:16 PM

well spotted!
Pretty hard to actually see that that valve when you need to

It's a valve that stays closed when you start the engine to help the catalysts (?) warm up faster and produce less pollution. I believe it's electrically controlled.

I think it also stays closed much of the time when you drive, to reduce exhaust noise and 'drone'.

It opens on full throttle

Search for plenty of threads to disable this valve so it remains open all the time (for better/louder exhaust sound)...though that could result in a drone at highway speed

justanotherx3 · 04-04-2020, 06:18 PM

Quote:

Originally Posted by satz

well spotted!
Pretty hard to actually see that that valve when you need to

It's a valve that stays closed when you start the engine to help the catalysts (?) warm up faster and produce less pollution. I believe it's electrically controlled.

I think it also stays closed much of the time when you drive, to reduce exhaust noise and 'drone'.

It opens on full throttle

Search for plenty of threads to disable this valve so it remains open all the time (for better/louder exhaust sound)...though that could result in a drone at highway speed

Fascinating; I'd love to hear from the outside what it sounds like open vs closed. Is this something that coding could do? It's only a turbo 4 so I doubt much difference open or closed.

DrSteveB · 04-04-2020, 06:45 PM

My BMW motorcycle has one on the exhaust as well for there same reasons satz listed.

freshxdough · 04-04-2020, 06:57 PM

Put it in sport. It opens the valve. For 100% always open pull the fuse or the connector when it's open.

BMWZ4 · 04-04-2020, 08:19 PM

Fuse # 203 in the trunk, right hand side panel.

WallyF · 04-05-2020, 11:29 AM

If I disconnect the connector or remove the fuse, will a computer throw a fault code and/or set off the CEL?

Thanks

Wallyf

suby01 · 04-05-2020, 02:24 PM

Quote:

Originally Posted by WallyF

If I disconnect the connector or remove the fuse, will a computer throw a fault code and/or set off the CEL?

Thanks

Wallyf

No CEL. But if you check your DME there will be error codes will state that there is some exhaust error. It doesn't break anything and it's completely reversible.
Some members even took their cars in for BMW service with the fuse removed. I wouldn't recommend that.
Heres a quick guide. Different exhaust sound since its a M but same steps and concept.

satz · 04-06-2020, 06:54 PM

I haven't tried this yet as I recall reading a couple of posts where they found that even when they replaced the fuse, the exhaust sound wasn't as loud as before?

Also some concern about the valve being stuck closed for example due to vibration (I guess due to no power getting through as fuse has been removed)?

Incidentally, is it Sport mode or only Sport Plus that apparently keeps the valve open?

freshxdough · 04-07-2020, 11:09 AM

Nobody at the dealer cares that the fuse is removed. Even if they see the fault they won't care. Unless you're complaining that the exhaust is making a weird noise or something directly related to it. Just FYI. Coming in with a tune on the other hand, they don't like that so much.

harperium · 04-07-2020, 04:28 PM

I went in for an oil change at the dealer; they had to put fuse 203 back in to update the blah blah blah, but then they actually pulled fuse 203 again for me before I picked it up.

I usually leave fuse 203 pulled, unless I'm on a long road trip or with lots of people in the car.

GoodGuyAvi · 04-07-2020, 04:32 PM

Quote:

Originally Posted by freshxdough

Nobody at the dealer cares that the fuse is removed. Even if they see the fault they won't care. Unless you're complaining that the exhaust is making a weird noise or something directly related to it. Just FYI. Coming in with a tune on the other hand, they don't like that so much.

absoluuuuutly agree

chicagofan00 · 04-07-2020, 06:22 PM

Quote:

Originally Posted by harperium

I went in for an oil change at the dealer; they had to put fuse 203 back in to update the blah blah blah, but then they actually pulled fuse 203 again for me before I picked it up.

I usually leave fuse 203 pulled, unless I'm on a long road trip or with lots of people in the car.

Fuse 203 shouldn't make a difference for being able to do the upgrade. Fuse 218 definitely needs to be in place for the updates to work.

04-04-2020, 05:17 PM	#1
justanotherx3 Private 9 Rep 55 Posts Drives: 2019 X3 30i Join Date: Jan 2020 Location: NC iTrader: (0)	What is the flap inside the left exhaust pipe? I have a 2019 X3 30i, and noticed that the left tail pipe has a flap about half a foot inside. I don't see on on the right tail pipe. Thoughts on what this is?
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04-04-2020, 06:16 PM	#2
satz Lieutenant Colonel 336 Rep 1,642 Posts Drives: 2019 BMW X3 M40i Join Date: Dec 2014 Location: A land down under iTrader: (0)	well spotted! Pretty hard to actually see that that valve when you need to It's a valve that stays closed when you start the engine to help the catalysts (?) warm up faster and produce less pollution. I believe it's electrically controlled. I think it also stays closed much of the time when you drive, to reduce exhaust noise and 'drone'. It opens on full throttle Search for plenty of threads to disable this valve so it remains open all the time (for better/louder exhaust sound)...though that could result in a drone at highway speed __________________ 2019 X3 M40i, Sophisto grey, H/K, pano Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K Previous: 2009 335i LCI, Bluewater
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04-04-2020, 06:45 PM	#4
DrSteveB Private First Class 32 Rep 164 Posts Drives: '18 540d, '18 X3, '10 335d Join Date: Aug 2019 Location: Asheville, NC iTrader: (0)	My BMW motorcycle has one on the exhaust as well for there same reasons satz listed.
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04-04-2020, 06:57 PM	#5
freshxdough BMW Elite Master Tech \| HV Gen 5 \| HV Specialist 3511 Rep 4,208 Posts Drives: 2024 iX 50 \| 2020 X3 M40i Join Date: Mar 2017 Location: Orange County iTrader: (0)	Put it in sport. It opens the valve. For 100% always open pull the fuse or the connector when it's open.
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04-04-2020, 08:19 PM	#6
BMWZ4 Major General 1910 Rep 5,105 Posts Drives: '23 X1/'23 Allroad Progressiv Join Date: Apr 2010 Location: Toronto iTrader: (1)	Fuse # 203 in the trunk, right hand side panel. __________________ '11 Z4 30i (retired);'11 X3 28i (retired); '15 M235i Stage 1 Dinan (recalled & crushed); '16 M235i Stage 3 Dinan (retired); '15 X3 28i (retired); '14 328i (retired), 2019 X3M40i (retired); Loaded '18 X1 (retired); Loaded '20 X3MC DG, Black/Tan Merino (retired); Loaded '23 X1 Cape York green and Red/Black interior; '23 Audi A4 Allroad Progressiv
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04-05-2020, 11:29 AM	#7
WallyF First Lieutenant 97 Rep 399 Posts Drives: 2023 BMW i4 eDrive40 Join Date: Oct 2005 Location: Fort Wayne, IN iTrader: (1) Garage List 2023 BMW i4 eDrive4 ... [0.00]	Will disconnecting the connector throw a Fault code If I disconnect the connector or remove the fuse, will a computer throw a fault code and/or set off the CEL? Thanks Wallyf
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04-06-2020, 06:54 PM	#9
satz Lieutenant Colonel 336 Rep 1,642 Posts Drives: 2019 BMW X3 M40i Join Date: Dec 2014 Location: A land down under iTrader: (0)	I haven't tried this yet as I recall reading a couple of posts where they found that even when they replaced the fuse, the exhaust sound wasn't as loud as before? Also some concern about the valve being stuck closed for example due to vibration (I guess due to no power getting through as fuse has been removed)? Incidentally, is it Sport mode or only Sport Plus that apparently keeps the valve open? __________________ 2019 X3 M40i, Sophisto grey, H/K, pano Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K Previous: 2009 335i LCI, Bluewater
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04-07-2020, 11:09 AM	#10
freshxdough BMW Elite Master Tech \| HV Gen 5 \| HV Specialist 3511 Rep 4,208 Posts Drives: 2024 iX 50 \| 2020 X3 M40i Join Date: Mar 2017 Location: Orange County iTrader: (0)	Nobody at the dealer cares that the fuse is removed. Even if they see the fault they won't care. Unless you're complaining that the exhaust is making a weird noise or something directly related to it. Just FYI. Coming in with a tune on the other hand, they don't like that so much.
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04-07-2020, 04:28 PM	#11
harperium Major 1313 Rep 1,064 Posts Drives: G80 M3cx Join Date: Dec 2016 Location: Chicago iTrader: (0)	I went in for an oil change at the dealer; they had to put fuse 203 back in to update the blah blah blah, but then they actually pulled fuse 203 again for me before I picked it up. I usually leave fuse 203 pulled, unless I'm on a long road trip or with lots of people in the car.
	Appreciate 0 Quote