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Why is one tail pipe so shiny and clean inside

1657 Views 29 Replies 17 Participants Last post by  makeadeel
My drivers side - inside exhaust pipe is still looking much newer than the other three exhaust pipes. Is this normal?
I have about 2300 miles on the clock.
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I have never gotten down to look at the depth of the exhaust . Even though this type of OCD is almost like becoming a Porsche proctologist you have me curious enough to look . My wife has the car now so it will have to wait .
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restrictor ? i have no idea what i am talking about.
I have never gotten down to look at the depth of the exhaust . Even though this type of OCD is almost like becoming a Porsche proctologist you have me curious enough to look . My wife has the car now so it will have to wait .
Thanks for the chuckle Larry. While I am fairly OCD, Ive never identified as having any “proctological” tendencies 🤣
I noticed the one clean pipe just walking up to the rear of the car. I did take a knee to take a clear picture so I could ask for some technical advice.
It’s not the pipe with the flapper/restrictor. You can see that in the picture below.
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I've read that a black exhaust is a sign of a problem with the fuel injectors.
While there may be nothing wrong with your car, since there is a difference between your exhaust pipes, you may want to take it in for the dealer to check your fuel injectors.

I also saw a MF post, in 2017, mentioning a recall for Porsche Macan fuel injectors. IDK if this is correct.
Thanks for the chuckle Larry. While I am fairly OCD, Ive never identified as having any “proctological” tendencies 🤣
I noticed the one clean pipe just walking up to the rear of the car. I did take a knee to take a clear picture so I could ask for some technical advice.
It’s not the pipe with the flapper/restrictor. You can see that in the picture below.
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I haven’t looked because my wife just got home and it’s dark. It will have to wait until tomorrow morning.

I don’t know what it could mean with the Macan or even if it’s normal. I do know that with the 997 it was the beginning warning sign of a problem, it’s one of the first things I tell someone who’s looking at used 997 cars. It might be nothing with the Macan, but I’m curious to have a look at mine .
My drivers side - inside exhaust pipe is still looking much newer than the other three exhaust pipes. Is this normal?
I have about 2300 miles on the clock.
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Only a truly anal person would worry about the color variation in the exhaust pipes on a new Macan. My suggestion: Drive the darn car and enjoy it. :rolleyes:
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You car has an "active" exhaust. A button on the console activates an electric valve (the "flapper" you mentioned in post 4). In normal mode the exhaust goes through three chambers in each muffler, and exists out one of the exhaust tubes on each muffler. When activated the exhaust goes through only one chamber in each muffler, and exists out of the other exhaust tubes on each muffler.

You probably have a broken "flapper".
i am wondering how my folks have looked up their exhaust pipe today? :p:eek:
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You car has an "active" exhaust. A button on the console activates an electric valve (the "flapper" you mentioned in post 4). In normal mode the exhaust goes through three chambers in each muffler, and exists out one of the exhaust tubes on each muffler. When activated the exhaust goes through only one chamber in each muffler, and exists out of the other exhaust tubes on each muffler.

You probably have a broken "flapper".
In this case there would be also a very small benefit in hp when flaps are open ?
Wow, when in normal mode, the exhaust uses the 2 inside outlets, but the driver side has some sort of restrictor, maybe something new to the gen 3 to aid fuel economy in normal mode?

I would say I notice my exhausts are much "sootier" on my turboed cars, likely due to running slightly richer air/fuel mixtures to provide a margin of safety to the boosted engines. My 718 GTS 4.0 (non turbo flat 6) has almost zero soot.

As others have mentioned I do look at my exhausts to both check for any potential issues and of course to clean them :)
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So, I was hoping someone would be able to tell me why one of my four tail pipes looks “brand new”, - like it hasn’t had any exhaust flow through it at all after 2,300 miles. It wasn’t hard to notice the shiny reflection from inside the one tail pipe while standing behind the car. It looks weird to me but I have no logical explanation.

You car has an "active" exhaust. A button on the console activates an electric valve (the "flapper" you mentioned in post 4). In normal mode the exhaust goes through three chambers in each muffler, and exists out one of the exhaust tubes on each muffler. When activated the exhaust goes through only one chamber in each muffler, and exists out of the other exhaust tubes on each muffler.

You probably have a broken "flapper".
The problem with this theory is that I don’t have a button to control the “flapper”. Perhaps this “flapper” closes during a cold start giving us that throaty roar when the engine starts? In any event, I don see how that would impact keep a different pipe from having more soot buildup. And I do get that wonderful roar every time I cold start this S.

My car seems to be running just fine so I really don’t want to bring it in and incur a diagnostic charge just to have my SA shrug his shoulders. Would a problem with one or more injectors throw a code? Should there be some performance issues associated with an injector problem?

Any of you DIYers out there really know what’s going on with my pipes?
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If the car is running ok without codes or performance issues it would seem normal. Sure it's somewhat curious. I think it might be related to exhaust pipe length. I don't believe the pipes are exactly equal in length and shape from the engine to the tip.
I'd look at the exhaust while the car is idling and have another person rev the engine a bit while you're looking at the exhaust coming from the pipes. If the exhaust looks black that typically means the air/fuel mix is too rich, which could be caused by several different factors and I would have it checked. If the exhaust looks normal, I wouldn't be concerned with it.
I looked at mine today . Now its true that the car is not cleaned up but they are both equally dirty.
Mine aren't evenly coated/dirty either. I always assumed it was because I run in normal ( butterfly exhaust closed) and sometimes in Sport ( valve open).
It's perfectly normal on my 95B.1 That flap is closed unless you are in sport or the RPMs go over 4K (I think it could be 3500 or 4500). After the first couple of years (mine turned 9 last week) they all evened out at some point :)
... I really don’t want to bring it in and incur a diagnostic charge just to have my SA shrug his shoulders. ...
Your MY 2023 is under factory warranty.
Why would you be charged a diagnostic charge?
If every vehicle of a certain model has one exhaust exit appearing dirtier than the other, it's likely due to the design of the exhaust system itself, and not indicative of a problem.

Exhaust gases will naturally follow the path of least resistance. The design of the exhaust system, including the length and configuration of the pipes, the positioning of components like mufflers and catalytic converters, and the splitting mechanism for the gases, can all influence the path that the exhaust gases take.

If the exhaust system isn't perfectly symmetrical or if the splitting mechanism isn't perfectly balanced, more exhaust gases (and thus more soot) might end up going through one exit than the other. This could cause one exit to appear dirtier over time.

Also, I’m pretty sure the Macan utilizes an H pipe and not an X. Would be interesting if anyone has an X pipe aftermarket with both exhausts dirty?
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