I believe starting in 2021, Mercedes made it such that the valves do not fully open unless under full throttle.

This likely was due to the new EU sound regulations.

They default to wide open when the car is off. However, simply disconnecting the motors will cause a fault code and reduced power.

Has anyone tried to disable the rear muffler exhaust valves by removing the actuator motors (but keeping them plugged in order to avoid a code) or some other method like an adapter/spacer or an aftermarket plug and play module?

Renntech makes a module to keep them open all the time.



https://www.renntechmercedes.com/ind...490-213-detail

Thanks for that.

Because I'm not sure how much better the sound would be, before spending
that amount of money, I was tempted to remove the actuators, zip tie the valves 100% open and
leave the actuators plugged in to see how it sounds.

I hesitate now though, thinking I might buy a problem reinstalling them in case they need to be re-formatted, etc....

Any thoughts?