So I noticed that on most days exhaust doesn't come out of my drivers side pipe only my passenger side. Had the dealer take a look at it. Dealer states that exhaust was indeed coming out but not at the rate as passenger side due to the exhaust system not being a true dual exhaust. Is this true ? they further state that vehicle was operating as designed. Has anyone noticed this ? I have a 2016 c300 4 Matic

 

This is what I've noticed as well. Especially during the winter time when you can see the gas better. Pretty sure it's normal. Passenger exhaust starts with more fumes and gets dirtier than the driver side. When I parked at work during winter time, I would look back at the rear of the car when locking the doors, both pipes had residual heat/gas coming out/evaporating. So they work, maybe just not at the same rate like your dealer is saying.

 

The pressurised exhaust gas takes the path of least resistance and therefore one side is more noticeable than the other!

 

Do the V6 cars have true dual exhaust, one from each bank? Cause my E350 has even distribution.

 

I imagine yes is the answer to your question.