Audi A5 Injector Issues Causing Multiple Engine Problems

I experienced something very similar with my 2018 A4 with the 2.0 gasoline engine last year. I have some experience working on cars but injection systems are pretty complex. The symptoms were identical, rough idle, misfires during cold starts, and terrible fuel economy. After initial diagnosis, it turned out the injection valves were heavily contaminated, restricting proper fuel delivery to the engine. The repair involved: Complete ultrasonic cleaning of all injectors, Replacement of 2 severely clogged injectors, New seals and gaskets, Full system calibration Total cost was 515 Euro including parts and labor. The difference in engine performance after the fix was night and day, smooth idle, proper power delivery, and normal fuel consumption returned. To help diagnose your specific case, could you share: Engine size and type, Current mileage, Type of fuel you normally use, How long the symptoms have been present, Any check engine lights or error codes This info would help determine if your A5 is facing the same injection system issues I encountered. Consider getting the fuel injectors tested before full replacement. Sometimes a professional cleaning service can resolve the issues without needing new parts.

Thanks for sharing your experience. My A5 has 86879 KM and just had its annual service last month. After reading your detailed response, it seems our issues match exactly. The engine performance problems started about 3 weeks ago, and the misfire is most noticeable during cold starts. Had the error codes read at a local shop, P0301 and P0302 showed up, pointing to cylinder 1 and 2 misfires. Good to hear the repair cost was reasonable in your case. Think I will get the injectors tested first before considering full replacement. Would using a fuel system cleaner additive help prevent these issues from happening again after the repair?

From my experience with the same issue on my A4, fuel system cleaners can definitely help as preventive maintenance. After my injector repair, I started using a quality fuel system cleaner every 15000km and havent experienced any misfire issues since. Those error codes you mentioned, P0301 and P0302, are exactly what my vehicle displayed. The fact that your engine performance problems appeared suddenly suggests contaminated or faulty injectors, just like in my case. The emissions issues and reduced engine performance are classic symptoms. One thing to note, the shop that did my repair mentioned that lower quality fuel can accelerate injector wear and contamination. Since the fix, I switched to higher grade fuel and noticed the engine runs noticeably smoother. The good news is that once fixed properly, these injection system issues rarely return if you maintain regular service intervals and use quality fuel. The repair completely resolved my vehicles performance problems, eliminating the cold start misfires and restoring normal fuel consumption. Would recommend having the injectors tested soon, as running the engine with faulty injectors can potentially cause additional issues over time.

Thanks for all the helpful information. Those error codes and symptoms definitely match what your A4 experienced. I just booked an appointment with a repair shop for next week to get the injectors tested and potentially cleaned or replaced. The vehicle has been getting premium fuel since new, but I will definitely start using fuel system cleaner as preventive maintenance once the repair is done. Makes sense to protect the injection system, especially given the repair costs involved. Really appreciate the detailed breakdown of your repair experience and costs. It helps to know what to expect and confirms my suspicion about the injectors being the likely culprit. Will update once I get the repair done and see if it resolves the misfire issues and rough running.