Mercedes E Klasse Misfire Issue

Misfires and rough idle, eh? Check engine light is a given with misfires. Could be a few things. Have you considered the ignition coils? They can cause similar symptoms. Or maybe a clogged fuel filter starving the engine? Is fuel pump pressure good?

Ignition coils are a possibility. But wouldn't a faulty coil usually trigger a specific code for that cylinder? And regarding the fuel pump, wouldn't that affect performance across the board, not just specific cylinders?

True, a coil usually throws its own code. Fuel pump issues can be widespread, but sometimes a partially failing pump only struggles under load, affecting some cylinders more. Given the injector suspicion, and the low mileage, maybe just get a diagnostic check at a workshop? They'll pinpoint it quickly.

You were right about the injector. Took it to a workshop; they confirmed it was defective. Replaced it, and the car's running smooth again. Total cost was 515€ Thanks for the input!