VW Taigo Running Rich, Engine Performance Issues

Having some experience with fuel system issues, I faced almost identical symptoms with my 2020 VW T-Cross with the 1.0 TSI engine. The check engine light, rough running, and especially that jerking during acceleration were exactly what I experienced. After diagnostic testing, the workshop found that one of the fuel injectors was defective, causing an inconsistent fuel spray pattern. This led to an overly rich mixture and poor fuel economy. The defective injector was disrupting the proper air-fuel ratio, which explained the rough running and power loss. The repair involved: Complete fuel injector testing, Replacement of the faulty injector, System reprogramming, Test drive to confirm proper operation Total cost was 515€ including parts and labor. After the repair, fuel consumption returned to normal and the engine ran smoothly again. To provide more specific advice for your case, could you share: Current mileage on your Taigo, Engine size and type, When you first noticed these symptoms, Any recent maintenance or repairs, Whether you notice any unusual smell from the exhaust, If the catalytic converter has ever been replaced This information would help determine if your issue is similar to what I experienced or potentially something different.

Thanks for sharing your experience. For reference, my Taigo has 17427km and is still within the original factory service schedule. After reading your response, I suspect it could indeed be a faulty injector. My symptoms match exactly what you described with the disrupted air-fuel ratio. The poor fuel economy and rough running are identical to your case. One additional detail I should mention, there is a slight fuel smell from the exhaust, which probably indicates excessive fuel in the system. The catalytic converter is original and has never been replaced. Would you recommend having all injectors tested, or is replacing just the problematic one typically sufficient? I want to avoid future issues if the others might be prone to failure too.

Based on our similar experiences with VW fuel system issues, I would strongly recommend having all injectors tested. In my case, while only one injector was initially faulty, a complete diagnostic test revealed that another injector was showing early signs of wear. The fuel smell you mention from the exhaust is a classic indicator of a rich mixture, which matches the pattern I experienced. When the oxygen sensor detects this rich condition, it tries to compensate, but with a faulty injector, it cant maintain the proper air-fuel ratio. In my follow-up maintenance 6 months after the initial repair, I had the remaining injectors replaced preventively, which cost an additional 380€. Looking back, doing all injectors at once would have saved money on labor costs. Important tips from my experience: Request a complete fuel system pressure test, Have all injectors flow-tested individually, Make sure they check the oxygen sensor readings, Consider preventive replacement if other injectors show wear The low mileage on your Taigo suggests this might be a manufacturing defect rather than wear-related failure, similar to my situation. You might want to check if this would be covered under warranty since your vehicle is relatively new. Would you like details about the specific testing process they used to diagnose my injectors? The workshop used some interesting diagnostic methods that proved very accurate.

Thanks, but I want to skip the testing details for now. My dealership appointment is next week, and I will raise these points about checking all fuel injectors and the complete fuel system. Your experience has been really helpful, especially knowing that preventive replacement might make sense in the long run. The manufacturing defect angle is worth pursuing, as my car should definitely still be under warranty. Will make sure to highlight the fuel smell from the exhaust and disrupted air-fuel ratio during the appointment, as these seem to be key indicators of the injector problem. Looking at how closely our cases match, with the rough running and rich mixture issues, I am fairly confident this will end up being an injector-related fix. Will update the forum once I get the diagnosis and repair completed, as it might help others with similar VW fuel system problems.