Coding out exhaust flaps on 2018 E63S
Thread Starter
Newbie
Joined: Apr 2026
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W213 E63S
Coding out exhaust flaps on 2018 E63S
Hi all,
I recently started getting the dreaded exhaust flap issue on my 2018 E63S, classic symptoms of limiting power by about a third - only happens intermittently (at the moment).
I understand you can have a tuner code them out altogether, but I'm not having much luck finding someone who will do it without having a full CPC tune - which I'm not keen on paying for if I'm honest as I'd like to keep the car as stock as possible. However, I was wondering if anyone had any experience of using a remote tuner to do it via OBD2? I found that ZAC Motorsport will do it (like here: https://www.zacmotorsport.co.uk/prod...4-401296cf41a8, has anyone had any experience of this?
I'm also happy to visit somewhere to have it done (would be my preferred option) here in the UK, if anyone has any recommendations?
Thanks in advance.....
Simon
I recently started getting the dreaded exhaust flap issue on my 2018 E63S, classic symptoms of limiting power by about a third - only happens intermittently (at the moment).
I understand you can have a tuner code them out altogether, but I'm not having much luck finding someone who will do it without having a full CPC tune - which I'm not keen on paying for if I'm honest as I'd like to keep the car as stock as possible. However, I was wondering if anyone had any experience of using a remote tuner to do it via OBD2? I found that ZAC Motorsport will do it (like here: https://www.zacmotorsport.co.uk/prod...4-401296cf41a8, has anyone had any experience of this?
I'm also happy to visit somewhere to have it done (would be my preferred option) here in the UK, if anyone has any recommendations?
Thanks in advance.....
Simon
MBWorld Fanatic!
Joined: May 2017
Posts: 1,725
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From: Southern California
2018 E63S AMG
Here's a post where someone came up with a mechanical fix for the issue.
https://mbworld.org/forums/w213-amg/...x-finally.html
https://mbworld.org/forums/w213-amg/...x-finally.html
MBWorld Fanatic!
Joined: Mar 2011
Posts: 2,487
Likes: 1,553
From: Canada
2023 E63S Wagon
The flaps are controlled in the CPC not the ECU, which is why the CPC needs to be tuned to code them out.
You can try (if it is a mechanic issue) the above, or if it is something else you can use a plug-in aftermarket harness like from ASR to keep them permanently open (see my signature). But this will only work if the valves are listening and not stuck, or, they maybe working fine physically but the sensor/signal is busted. Without the car knowing the flaps are able to fully open, it withholds boost to not destroy the engine.
I have a CPC module for sale, from Black Boost. It can be virginized and set to your VIN (the original stock OEM ones cannot be reprogrammed FYI). https://mbworld.org/forums/market/926365
And keep in mind there are other things that can cause this low boost issue - mine was actually an intake diverter valve, same symptoms:
https://mbworld.org/forums/w213-amg/...ml#post9257253
The Fix:
https://mbworld.org/forums/w213-amg/...ml#post9263488
https://mbworld.org/forums/w213-amg/...ml#post9263488
https://mbworld.org/forums/w213-amg/...ml#post9263488
You can try (if it is a mechanic issue) the above, or if it is something else you can use a plug-in aftermarket harness like from ASR to keep them permanently open (see my signature). But this will only work if the valves are listening and not stuck, or, they maybe working fine physically but the sensor/signal is busted. Without the car knowing the flaps are able to fully open, it withholds boost to not destroy the engine.
I have a CPC module for sale, from Black Boost. It can be virginized and set to your VIN (the original stock OEM ones cannot be reprogrammed FYI). https://mbworld.org/forums/market/926365
And keep in mind there are other things that can cause this low boost issue - mine was actually an intake diverter valve, same symptoms:
https://mbworld.org/forums/w213-amg/...ml#post9257253
The Fix:
https://mbworld.org/forums/w213-amg/...ml#post9263488
https://mbworld.org/forums/w213-amg/...ml#post9263488
https://mbworld.org/forums/w213-amg/...ml#post9263488
Last edited by I.T. Guy; Apr 30, 2026 at 10:23 AM.
Thread Starter
Newbie
Joined: Apr 2026
Posts: 2
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W213 E63S
Thanks for your reply, but with respect you didn't answer my question.
I'm asking if the valves can be coded out in isolation without the CPC tune or is the CPC tune the only option?
Secondly, codes 100% confirmed that the right hand actuator is failing, no other issues.
I'm asking if the valves can be coded out in isolation without the CPC tune or is the CPC tune the only option?
Secondly, codes 100% confirmed that the right hand actuator is failing, no other issues.
Member
Joined: Jan 2021
Posts: 231
Likes: 138
From: Arizona
2019 E63S and 2014 CLS 63S
Thanks for your reply, but with respect you didn't answer my question.
I'm asking if the valves can be coded out in isolation without the CPC tune or is the CPC tune the only option?
Secondly, codes 100% confirmed that the right hand actuator is failing, no other issues.
I'm asking if the valves can be coded out in isolation without the CPC tune or is the CPC tune the only option?
Secondly, codes 100% confirmed that the right hand actuator is failing, no other issues.
MBWorld Fanatic!
Joined: Mar 2011
Posts: 2,487
Likes: 1,553
From: Canada
2023 E63S Wagon
+1
The non-cpc exhaust flap coding that exist merely mimic pushing the exhaust flap louder button that is already in the car. This only opens the flaps over 4000 RPM or something like that.
The non-cpc exhaust flap coding that exist merely mimic pushing the exhaust flap louder button that is already in the car. This only opens the flaps over 4000 RPM or something like that.
MBWorld Fanatic!
Joined: Mar 2011
Posts: 2,487
Likes: 1,553
From: Canada
2023 E63S Wagon
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Super Member
Joined: Oct 2016
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From: Destin FL
2018 E63 AMG S
Hi all,
I recently started getting the dreaded exhaust flap issue on my 2018 E63S, classic symptoms of limiting power by about a third - only happens intermittently (at the moment).
I understand you can have a tuner code them out altogether, but I'm not having much luck finding someone who will do it without having a full CPC tune - which I'm not keen on paying for if I'm honest as I'd like to keep the car as stock as possible. However, I was wondering if anyone had any experience of using a remote tuner to do it via OBD2? I found that ZAC Motorsport will do it (like here: https://www.zacmotorsport.co.uk/prod...4-401296cf41a8, has anyone had any experience of this?
I'm also happy to visit somewhere to have it done (would be my preferred option) here in the UK, if anyone has any recommendations?
Thanks in advance.....
Simon
I recently started getting the dreaded exhaust flap issue on my 2018 E63S, classic symptoms of limiting power by about a third - only happens intermittently (at the moment).
I understand you can have a tuner code them out altogether, but I'm not having much luck finding someone who will do it without having a full CPC tune - which I'm not keen on paying for if I'm honest as I'd like to keep the car as stock as possible. However, I was wondering if anyone had any experience of using a remote tuner to do it via OBD2? I found that ZAC Motorsport will do it (like here: https://www.zacmotorsport.co.uk/prod...4-401296cf41a8, has anyone had any experience of this?
I'm also happy to visit somewhere to have it done (would be my preferred option) here in the UK, if anyone has any recommendations?
Thanks in advance.....
Simon
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