GLC 43
Super Member
Joined: Feb 2016
Posts: 697
Likes: 104
From: Taiwan
GLC43, X P100D, S P100D, CT200H
Anything that you modify will void that part of the warranty. But nothing ever happens to the exhaust anyways so its usually among the 1st things that people change. I change my mid pipes and mufflers. Sounds mean.
Dual midpipes without resonators, valved muffler. Mid Pipe diameter about 2x 2.5inches.
Stock Cats.
MBWorld Fanatic!
Joined: Feb 2016
Posts: 1,577
Likes: 264
From: Portland, OR
C450, GLC43
DameMD on the GLC43 subforum claims he's had good results with a resonator delete. Search for his thread for the details. I have thought about doing the same but my GLC43 is also our "road trip" car so I'm a little nervous about inducing drone.
Super Member
Joined: Feb 2017
Posts: 703
Likes: 136
From: Northeast, USA
GLC43, GTI, X3, Mazda3
See this thread if worried about drone... https://mbworld.org/forums/c450-c43-...ml#post7592485 resonators.
Junior Member
Joined: Nov 2018
Posts: 38
Likes: 2
2017 Mercedes AMG C43 Coupe
To answer your original question, YES it will void the warranty on your OEM exhaust. Is it a big deal? No. As long as you purchase and properly install a quality after market exhaust system you should be 100% fine. When you take in your car for services or whatnot, most dealerships won't even say anything. The issue is if you have an problem with your aftermarket exhaust and take it to mercedes to fix, obviously mercedes warranty will not cover an aftermarket exhaust. Good luck 
