Mercedes R Klasse Engine Running Issue Resolved

I also drive a Mercedes R Klasse, although I can't say I'm intimately familiar with the model year. I had a similar problem not too long ago. Check engine light, rough running. Before you dive into sensors and pumps, have you considered a simple visual inspection of the exhaust system? A small leak can cause some pretty weird issues. Is the jerking consistent, or only under certain conditions? Does it seem to get worse when the engine is cold?

The jerking seems more pronounced when the engine is cold, yes. I will visually inspect the exhaust system as you suggested. Could a small exhaust leak really cause such noticeable jerking and trigger the check engine light? I was under the impression that an exhaust leak would primarily affect emissions and fuel economy, not necessarily cause such rough running. I am really not sure about this.

Yes, an exhaust leak, especially near the front of the system, can definitely cause those symptoms. The engine's sensors are very sensitive. It messes with the readings and the engine management system compensates poorly, leading to the jerking and the check engine light. That being said, I am not 100% sure, but given your symptoms and the potential for misfires, it's worth investigating before you start replacing things like fuel injectors or the crankshaft sensor. If you're not comfortable doing a thorough inspection yourself, I would suggest taking it to a trusted workshop. They should be able to pinpoint the leak quickly. And I wouldn't rule out spark plugs either, but the exhaust is a good place to start.

I followed your advice and had the exhaust system checked at a workshop. Turns out there was indeed a small leak near the manifold. They repaired it for 265€, and the engine is now running smoothly. The check engine light is off, and the jerking is gone. I appreciate your guidance in pointing me in the right direction!