RS5 Fuel Injection Woes: Poor Performance & Hard Starts

The symptoms you describe with your RS5 match exactly what I experienced on my 2015 Audi S5. The rough running, difficult cold starts, and increased fuel consumption clearly point to dirty fuel injectors affecting vehicle performance. In my case, the repair involved a complete fuel injection system cleaning and replacement of two clogged injectors. The carbon buildup was causing serious emissions issues and inconsistent fuel delivery. These symptoms should not be ignored as they can lead to more severe engine damage if left untreated. The repair process included: Complete ultrasonic cleaning of remaining injectors, Replacement of 2 damaged injectors, Fuel system pressure test, Computer system reset, Test drive to confirm proper operation After the repair, the engine returned to smooth operation with normal fuel consumption and proper cold starts. The entire process was significant but necessary to prevent further engine damage and restore proper performance. For accurate diagnosis, make sure the shop has specialized Audi diagnostic equipment. Clogging of injectors is a known issue on these direct injection engines, requiring periodic maintenance to prevent recurrence.

Thanks for sharing your experience with the S5 injector problems. Our RS5 issues sound identical, especially the rough engine performance and excess gasoline usage. The repair process you outlined seems comprehensive. Did the misfire issues completely resolve after the repair? Also curious about the final cost since I am trying to budget for this fix. Any unexpected problems pop up in the months following the injector service?

Thanks for asking about the follow-up results. The repair on my RS5 was completely successful, with the misfire issues fully resolved after replacing the defective injection nozzle. The engine now runs smoothly without any rough performance or excess fuel consumption problems. The total repair cost came to 515 Euro for fixing the clogged injection valve, which included the complete diagnostic work and system testing. While this might seem significant, it was worth every cent considering the vehicle now performs like new. In the six months since the repair, no additional injection-related problems have emerged. The cold starts are perfect, and fuel consumption has returned to normal levels. The thorough cleaning and replacement work prevented any potential cascade of engine issues that often result from prolonged injection system problems. Regarding long-term maintenance, regular fuel system cleaning helps prevent future clogging and maintains optimal engine performance. This preventive approach costs far less than dealing with complete injection system failure.

Thanks everyone for the great input. Just wanted to update on how my RS5 situation turned out. Finally took it to a new mechanic who properly diagnosed the injection system problem. The repair ended up being very similar to what others described. My issue stemmed from two completely clogged injectors that were causing the rough engine performance and excessive gasoline consumption. The mechanic performed a complete fuel system cleaning and replaced three faulty injectors. Total repair cost came to 780 Euro, slightly higher than expected but the results were worth it. The engine runs perfectly smooth now, cold starts are no longer an issue, and fuel consumption is back to normal. The emissions test also showed significant improvement. Had the work done about three weeks ago and so far no unexpected issues have popped up. The vehicle performs like new during acceleration and the rough idle is completely gone. Really glad I got this fixed before it led to more serious engine damage. Going forward, will definitely stay on top of the injection system maintenance to prevent future problems. Thanks again for helping me avoid another costly misdiagnosis.