rp-24

Hi all,

I have a 2019 facelifted C43 with PE, since April this year I can no longer hear any pops or crackles coming from the exhaust when it sports + mode. Before this I could produce the noises very easily, when downshifting from high revs or when I would rev up past 3000 rpm and take my foot off the gas it would produce those lovely crackle/popping noises. Now when i put the car in sports+ the exhaust still sounds loud but there is no pops or crackles.

I recall this happened after I filled up fuel at my normal garage(Shell V-power), and since then I have not heard a single crackle regardless of how hard Ive tried. From reading online I thought it could have been an ECU issue that may have "deleted" the noises and so last week I took it to the Mercedes dealership and having explained the issue they updated the ECU (and carried out a routine B service). Unfortunately this hasn't resolved anything and I am still faced with the same problem.

I would be grateful if anyone has any suggestions please do let me know. The car doesn't feel the same without those beautiful exhaust noises and really want to get the issue fixed!

amgesp

Have the dealership replaced exhaust if possible sux this is happening 🥺😭

allanyeung99

They updated the ECU? Would explain why, my c400 doesnt crackle or pop like C450s and C43s cause of the "AMG" tune that C450s and C43s has.

amgesp

This whole time I thought he had a c43 amg like me but yeah I'm clueless can't help anyone chime in and yes I love the pop's crackles 😆👍🏻

Spaggettio

check the valves on the exhaust are functioning correctly

Ramsino

The crackles and pops are purely ECU controlled and has nothing to do with the valve. If you can noticeably hear your exhaust getting louder when your turn on PE, then your valves are opening correctly. The ECU controls the pops on upshifts and crackles on downshifts, and it is only enabled when your engine is set to Dynamic mode (Sport+).

stockbmw

Possible you put low grade gas and engine retarded the timing because of knocking and ecu can't control the detonation well then if it had higher octane fuel.

Try another gas station, maybe the shell you went to cheaped out or mixed up the gas grade when you were there last.

rp-24

Hi,

Just an update in case it may help others in the future. I took my car to Mercedes in regards to the issue where I could no longer get the car to make any burbles/crackles on the overrun.

They ran a fault code and it came up with the Petrol Particulate Filter (PPF/OPF) was showing excess levels of soot. I don't put many miles on my car or take my car on long journeys and this had caused the PPF to clog up. Unfortunately with the new petrol particulate filter they are not able to perform a forced regeneration to clear out the build up unlike diesel cars. So they kept my car for a week and took them on long journeys to perform passive regenerations and after 500 miles of travelling the PPF was showing lower levels of particulate. I got the car back today and can confirm the burbles/crackles have returned.

stockbmw

You let someone else drive your ride and put 500 miles on your baby?

19’43s

@stockbmw imo dude should’ve just tuned the car if he wants real burbles without catless downpipes (easy to revert back to stock without getting “caught”), 500 miles seems like a lot hopefully they didn’t do no coffee runs or drove over pot holes

eatmydust

I get crackle and pops even in comfort mode?

2020 C43 sedan

Ramsino

There are crackles here and there but the loud POPS and BANGS on upshifts above 4500 rpm is not there unless Sport+ is on or the engine is changed to Dynamic mode (I have PE).

eatmydust

Wow didn't know that or notice. Even in comfort mode my pops are ridiculous haha, never thought there was a difference.

Cowboy11

So you basically saying they drove the car for you and put on the milage to fix the issues.😂

Paul_A45

Hello people, I’m a bit late not sure if anyone still uses this thread.. but..

I’ve had 3 A45’s now, two pre facelifts with standard exhaust, now I have the facelift with the performance exhaust, it’s fully kitted out every optional extra, race mode the works…

but I get no pops or bangs on uplift at all unless I’m around 6000rpm in S+ / Race? But with the two previous I got them at 2000rpm on uplift for fun… anyone know the reason for this? Is my perf exhaust not working? I can never hear the valve opening… should I? There doesn’t seem to be any difference in sound from C to S+ other than a slight burble on upshift in S+ and idle noise?

cheers !

eLLeDB53AMG

Wild I am having this issue in my gle 53 which also would pop in comfort and has stopped 3 days ago, svce is useless telling me it didn’t pop in comfort (funny i drive the car daily and it did for over a year) so i am at a loss and and am kinda mad 🤦🏼‍♀️

Muskokamarc

My stock 17 C43 coupe occasionally pops and crackles in comfort. The weirdest thing the car does is pop and crackle in ECO mode when i release the throttle and it enters 'glide' mode. I don't hate it lol, but not sure if it's operating correctly... I honestly don't notice too much difference when I'm in comfort and open/close the valves.

eLLeDB53AMG

I have a gle 53 and i have never used eco actually lol but it still pops and whatever in sport and sport +. So last Friday it just stopped for no reason no lights on the dash. I tried everyday lol and no change…I drove home from work on Thursday it happened then 3 minutes my tire thing came on and i had a flat with a nail ugh got a new tire today (THANK GOD FOR THE TIRE PACKAGE) but plannkng to run my gas tank to E and refill elsewhere and try again

djjs

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, but my method probably would not work for those of you living stateside. Due to emission violations? LOL