Mercedes C Klasse Hybrid Engine Running Rich

That sounds like a real pain A rich running engine can definitely cause those symptoms Since the check engine light is on, have you had the car scanned for error codes That's the first step The error code will give you or a mechanic a better idea of what's going on Besides the injectors, which you mentioned, a faulty oxygen sensor can also cause the engine to run rich The oxygen sensor measures the amount of oxygen in the exhaust gas If it's not working correctly, it might tell the car's computer that there's not enough oxygen, which leads to the computer adding more fuel Another possibility is a problem with the catalytic converter But you should start with those error codes, it'll really help narrow down the possibilities One more thing, have you checked your spark plugs Old or fouled plugs can contribute to poor combustion and similar symptoms

Thank you for the information I appreciate the detailed explanation Could you elaborate a bit more on how a faulty oxygen sensor might cause these specific issues I'm not entirely sure how that sensor influences the engine's performance, and what the ECU is doing with the signal Also how can I interpret the error codes

Ok, so the oxygen sensor is basically telling the car's computer (the ECU - Engine Control Unit) how much oxygen is in the exhaust after the fuel has been burned in the engine If the sensor is bad, it might report that there's not enough oxygen, even when there is plenty The ECU then thinks the engine is running lean (not enough fuel) and compensates by injecting more fuel That's what causes the rich running condition. As for interpreting the error codes, a standard OBD2 scanner will give you a code that looks something like 'P0172' (System Too Rich) You can search for these codes online, and they'll give you a description of the problem However, that code doesn't necessarily mean a specific part is faulty It just indicates a problem area Given your mileage and the symptoms, it really does sound like the fuel injectors could be the culprit. Honestly, at this point, I would take it to a reputable mechanic to get a proper diagnosis It can be tricky to pinpoint the exact cause without the right tools and expertise Better to spend a little money on a diagnosis than to start replacing parts at random

Thank you again for the thorough explanation and advice I took the vehicle to a workshop, and after diagnosis, it was indeed determined that one of the fuel injectors was defective The injector was replaced, and the total repair cost was 515€ The car now runs perfectly again Your insights were very helpful in understanding the potential issues