Audi A5 Stalling: Tank Valve Issue Symptoms Explained

I had a very similar issue with my 2021 Audi A4 last summer. Having some experience with EVAP system problems, I initially thought it was just the purge valve, but it turned out to be more complex. After the check engine light came on and experiencing those same stalling symptoms, I took it to my regular workshop. The diagnostic revealed clogged ventilation hoses in the EVAP system. The debris accumulation was preventing proper tank ventilation, causing the rough running and stalling issues you described. The complete repair included cleaning the system and replacing a few hoses, totaling 175 Euro. Since the fix, the car has been running smoothly with no check engine lights or stalling problems. Before suggesting specific solutions, could you share: Have you scanned for error codes? Does the stalling happen more frequently after refueling? Are you noticing any fuel smell? How many miles/kilometers are on your A5? This information would help determine if your issue matches what I experienced, as EVAP system problems can have various root causes.

Thanks for the input. Currently showing 146753 KM on the odometer. Yes, I did scan for codes using an OBD reader which showed P0441 and P0455 related to the EVAP system. The stalling definitely gets worse after refueling, and there is a faint fuel smell when the car sits parked. Last service was done 2 months ago during which they replaced the gas cap since it showed signs of wear, but the problem persists. The insights about the clogged ventilation hoses are helpful, will have the workshop check those specifically during the upcoming repair.

Thanks for providing those details, those are exactly the same error codes I encountered with my A4. The fact that you're experiencing increased stalling after refueling and a fuel smell strongly points to an EVAP system issue, just like in my case. Having gone through this, I can confirm that replacing the gas cap alone often won't resolve these symptoms. While the tank ventilation system includes the cap, the clogged ventilation hoses I mentioned were the root cause. The purge valve was actually working fine, but couldn't function properly due to the blocked hoses. With your mileage being similar to what mine was when the issue occurred (I was at around 140000 KM), this is a common wear point for these components. The emission system warning combined with those specific codes typically indicates restricted flow in the EVAP system. One thing I learned through my repair, make sure they check the entire fuel tank ventilation pathway, not just individual components. In my case, they initially focused on the purge valve but discovered the hose blockage only after a more thorough inspection. The repair process was straightforward once they identified the correct issue, and my car has been running perfectly for 25000 KM since then with no check engine lights or stalling problems.

This is really helpful information, and matches my situation perfectly. Having the same codes and similar mileage gives me confidence about the diagnosis. Will definitely request a complete EVAP system inspection focusing on those ventilation hoses when I take it in for repair next week. The fuel smell and post-refueling stalling matches what you experienced too. Good to know the automotive repair was straightforward once they identified the root cause. I was worried about potential fuel tank issues, but it sounds like the ventilation pathway is the more likely culprit. The emission system warnings and engine light have been concerning, so it's reassuring to hear your car has run problem-free for 25000 KM after fixing the hoses. Thanks for sharing your experience, it's given me a much clearer picture of what to expect during the repair process.