VW Virtus Engine Misfire: Symptoms and Solutions

I experienced something very similar with my 2021 VW Jetta last year. I have some experience working on cars, mainly doing basic maintenance like changing air filters and spark plugs. The symptoms you describe sound exactly like what I dealt with, rough idle, misfiring, and jerking during acceleration. After a thorough inspection, my workshop found a significant leak in the exhaust system near the manifold. The leak was causing incorrect readings in the oxygen sensors, which led to the engine running rich and misfiring. The total repair came to 265€, which included replacing the damaged exhaust components and gaskets. The repair completely resolved the rough idle and misfire issues. Before jumping to conclusions, it would help to know: How many kilometers are on your Virtus? Have you recently had any other repairs done? Did you notice any unusual exhaust sounds or smells before these symptoms started? When was your last timing belt service? A proper diagnosis is crucial since similar symptoms can also be caused by failing ignition coils or fouled spark plugs. The workshop should perform a thorough exhaust system pressure test to confirm if this is your issue.

My vehicle has 32751km on the odometer. Thank you for your detailed response. Your suggestion about checking the exhaust system is interesting, but I noticed the fuel injectors were not cleaned during my last service. The rough idle and engine misfire symptoms started shortly after filling up at a new station, which makes me suspect fuel quality or clogged injectors might be the culprit. The air filter is also due for replacement according to my service schedule. My understanding is these issues could be linked to dirty fuel injectors or a clogged air filter restricting proper air flow to the engine. Would it make sense to start with these basic maintenance items before diving into more complex exhaust system diagnostics?

Thanks for providing those additional details about your Virtus. After dealing with similar issues on my Jetta, I want to share some important follow-up points. While fuel quality and dirty injectors can definitely cause these symptoms, my experience suggests being cautious about assuming thats the only issue. When my Jetta showed identical symptoms, I initially focused on fuel injector cleaning and changing the air filter, but the problems persisted. The timing with the new fuel station is noteworthy, but in my case, the root cause turned out to be a combination of issues. Beyond the exhaust leak, I also had a failing oxygen sensor that was sending incorrect signals to the ECU. Since your Virtus has relatively low mileage, I suggest having the workshop perform: 1. A fuel system cleaning service 2. Air filter replacement 3. Basic diagnostics to check oxygen sensor readings 4. Spark plug inspection The total cost for all this preventive work on my Jetta was around 350€, but it provided peace of mind knowing all potential causes were addressed. A quick word about the crankshaft sensor, while checking the other components, have them verify its functioning too, as faulty readings can cause similar jerking symptoms during acceleration.

Thank you for your insights regarding the exhaust system and oxygen sensor checks. I agree its smart to be thorough rather than just assuming its fuel-related. My main concern about visiting the workshop immediately is the cost, since the vehicle is relatively new with just 32751km. I will start with the overdue air filter replacement and fuel system cleaning as these are straightforward maintenance items that could resolve the rough idle issues. However, your point about the crankshaft sensor and oxygen sensor readings makes sense. If the basic maintenance doesnt improve the situation, I will have the workshop perform their full diagnostic testing. The jerking during acceleration is concerning enough that I dont want to risk causing additional engine damage by waiting too long. I have scheduled the initial maintenance for next week and will update once I know if the rough idle and misfire problems improve after addressing these basic items. The total quoted cost for the air filter replacement and fuel system cleaning is 180€, which seems reasonable as a first step.