No more pops and crackles on c43 w/ performance exhaust
MBWorld God!
Joined: Dec 2019
Posts: 32,495
Likes: 6,347
Newbie
Joined: Feb 2024
Posts: 1
Likes: 0
c450. amg
Honestly, I don't know and couldn't figure out the ethanol content I just know it's 91 octane as that's the highest available around me. However, I'm happy to say that the pops and bangs have returned (even coming down from redline)! I plugged in an obd2 and deleted the only code that popped up, but it looked like it had something to my outter temp gauge (like weather temp), but I deleted it nonetheless and first time I put it back into sport plus everything was back to normal. Still don't really know what the exact issue was, but happy everything is back to normal!
please i also have the same issues can you help ???
MBWorld Fanatic!
Joined: Apr 2023
Posts: 1,568
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From: Occupied Palestine
2025 Maserati Grecale Folgore and 2024 Jaguar F-PACE SVR
bad for your catalytic converter anyways... gas is supposed to combust in the combustion chamber not your exhaust, hence the name. 
Junior Member
Joined: Jan 2012
Posts: 18
Likes: 7
From: Taiwan
W203 C55, W245 B170
Not trying to revive an old thread, but this is the story.
Burble suddenly disappear is the cause of a A/F ratio or Exhaust related DTC stored in ECU.
You could try to clear it, the sound will return. But as soon as the fault logs again it will disappear.
It's part of the soft-limp safeguard within the SG Exhaust sound generator control unit and ECU
I am currently working on solving this issue for one of my customer with aftermarket downpipe.
Apparently his DP did not have proper O2 sensor fittings and they were either hacked on or not even plugged in.
He will get Cat efficiency low DTC on both banks and his burble will stop working.
I've already turned off his lambda correction leaving only CO correction and lowered his exhaust governor down from EU6 to EU4 STP and from CARB to F-EPA
He no longer has CEL lit up, but the codes are still reoccurring in some intervals of 4 to 5 days. (about the time for LT trim to set in)
My next move is to disable his NOX and check SG sound unit coding see if there's anything can be fiddled with.
BTW, to code MED177V6LA you need to unlock both Level 09 and Level 0B seedkey securities.
Will update if this can be solved.
Burble suddenly disappear is the cause of a A/F ratio or Exhaust related DTC stored in ECU.
You could try to clear it, the sound will return. But as soon as the fault logs again it will disappear.
It's part of the soft-limp safeguard within the SG Exhaust sound generator control unit and ECU
I am currently working on solving this issue for one of my customer with aftermarket downpipe.
Apparently his DP did not have proper O2 sensor fittings and they were either hacked on or not even plugged in.
He will get Cat efficiency low DTC on both banks and his burble will stop working.
I've already turned off his lambda correction leaving only CO correction and lowered his exhaust governor down from EU6 to EU4 STP and from CARB to F-EPA
He no longer has CEL lit up, but the codes are still reoccurring in some intervals of 4 to 5 days. (about the time for LT trim to set in)
My next move is to disable his NOX and check SG sound unit coding see if there's anything can be fiddled with.
BTW, to code MED177V6LA you need to unlock both Level 09 and Level 0B seedkey securities.
Will update if this can be solved.
Last edited by djjs; Jul 16, 2024 at 03:16 PM.
Newbie
Joined: Mar 2025
Posts: 9
Likes: 0
2017 C43
Not trying to revive an old thread, but this is the story.
Burble suddenly disappear is the cause of a A/F ratio or Exhaust related DTC stored in ECU.
You could try to clear it, the sound will return. But as soon as the fault logs again it will disappear.
It's part of the soft-limp safeguard within the SG Exhaust sound generator control unit and ECU
I am currently working on solving this issue for one of my customer with aftermarket downpipe.
Apparently his DP did not have proper O2 sensor fittings and they were either hacked on or not even plugged in.
He will get Cat efficiency low DTC on both banks and his burble will stop working.
I've already turned off his lambda correction leaving only CO correction and lowered his exhaust governor down from EU6 to EU4 STP and from CARB to F-EPA
He no longer has CEL lit up, but the codes are still reoccurring in some intervals of 4 to 5 days. (about the time for LT trim to set in)
My next move is to disable his NOX and check SG sound unit coding see if there's anything can be fiddled with.
BTW, to code MED177V6LA you need to unlock both Level 09 and Level 0B seedkey securities.
Will update if this can be solved.
Burble suddenly disappear is the cause of a A/F ratio or Exhaust related DTC stored in ECU.
You could try to clear it, the sound will return. But as soon as the fault logs again it will disappear.
It's part of the soft-limp safeguard within the SG Exhaust sound generator control unit and ECU
I am currently working on solving this issue for one of my customer with aftermarket downpipe.
Apparently his DP did not have proper O2 sensor fittings and they were either hacked on or not even plugged in.
He will get Cat efficiency low DTC on both banks and his burble will stop working.
I've already turned off his lambda correction leaving only CO correction and lowered his exhaust governor down from EU6 to EU4 STP and from CARB to F-EPA
He no longer has CEL lit up, but the codes are still reoccurring in some intervals of 4 to 5 days. (about the time for LT trim to set in)
My next move is to disable his NOX and check SG sound unit coding see if there's anything can be fiddled with.
BTW, to code MED177V6LA you need to unlock both Level 09 and Level 0B seedkey securities.
Will update if this can be solved.
Last edited by ehsan21; Mar 22, 2025 at 08:00 PM.
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MBWorld God!
Joined: Dec 2019
Posts: 32,495
Likes: 6,347
Not trying to revive an old thread, but this is the story.
Burble suddenly disappear is the cause of a A/F ratio or Exhaust related DTC stored in ECU.
You could try to clear it, the sound will return. But as soon as the fault logs again it will disappear.
It's part of the soft-limp safeguard within the SG Exhaust sound generator control unit and ECU
I am currently working on solving this issue for one of my customer with aftermarket downpipe.
Apparently his DP did not have proper O2 sensor fittings and they were either hacked on or not even plugged in.
He will get Cat efficiency low DTC on both banks and his burble will stop working.
I've already turned off his lambda correction leaving only CO correction and lowered his exhaust governor down from EU6 to EU4 STP and from CARB to F-EPA
He no longer has CEL lit up, but the codes are still reoccurring in some intervals of 4 to 5 days. (about the time for LT trim to set in)
My next move is to disable his NOX and check SG sound unit coding see if there's anything can be fiddled with.
BTW, to code MED177V6LA you need to unlock both Level 09 and Level 0B seedkey securities.
Will update if this can be solved.
Burble suddenly disappear is the cause of a A/F ratio or Exhaust related DTC stored in ECU.
You could try to clear it, the sound will return. But as soon as the fault logs again it will disappear.
It's part of the soft-limp safeguard within the SG Exhaust sound generator control unit and ECU
I am currently working on solving this issue for one of my customer with aftermarket downpipe.
Apparently his DP did not have proper O2 sensor fittings and they were either hacked on or not even plugged in.
He will get Cat efficiency low DTC on both banks and his burble will stop working.
I've already turned off his lambda correction leaving only CO correction and lowered his exhaust governor down from EU6 to EU4 STP and from CARB to F-EPA
He no longer has CEL lit up, but the codes are still reoccurring in some intervals of 4 to 5 days. (about the time for LT trim to set in)
My next move is to disable his NOX and check SG sound unit coding see if there's anything can be fiddled with.
BTW, to code MED177V6LA you need to unlock both Level 09 and Level 0B seedkey securities.
Will update if this can be solved.
