Hey, sounds like a problem with a defective lambda sensor. I recently had a similar problem with my 2015 Mercedes CLA. My symptoms were very similar: black smoke, loss of power and strong-smelling exhaust. The garage replaced the lambda sensor and carried out a software reset. It wasn't a huge job, but it shouldn't be ignored, as a defective lambda sensor has a negative effect on the exhaust values and can damage the engine in the long term. It's best to have it checked quickly so that you don't risk any major consequential damage. Best regards!

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Hey, thanks for the info! That sounds pretty similar to my problem. Do you remember how much you paid to replace the lambda sensor? And has anything else happened since then or is everything running smoothly again? Best regards!

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Hey, yes, I still remember exactly. I paid €375 to replace the defective lambda sensor. Since then, the exhaust aftertreatment has been working perfectly again and I haven't had any more problems. The engine is now running smoothly again and the black smoke has also disappeared. So, I would really recommend that you take your car to a mechanic as soon as possible before it gets worse. Best regards!

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Hey, thanks for the detailed answer! That reassures me a little. I will definitely make an appointment with my garage as soon as possible. Hopefully I'll get the problem fixed as quickly and easily as you did. It would be really cool if it's just the lambda sensor and nothing more. Still, it's really bad how quickly something like this can happen with all these modern cars. Well, thanks again for your help! Best regards!

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