Audi Q2 Stalling Issue: Tank Ventilation Warning Signs

Had a very similar issue with my 2016 Q3 1.4 TFSI last year. As someone with moderate experience working on cars, I first thought it was just a loose gas cap, but the check engine light persisted. The symptoms matched exactly, engine stalling at idle and persistent warning lights. After some basic troubleshooting, took it to a workshop where they diagnosed clogged ventilation hoses in the tank ventilation system. The pressure sensor was reading incorrect values due to the blockage, causing the emission system to malfunction. The repair involved cleaning out the hoses and replacing a few components in the ventilation system. Total cost was 175 Euro, which included diagnostic time and parts. Since the fix, no more stalling or warning lights. For more specific advice about your Q2, could you share: Current mileage, Any recent work done on the fuel system, Whether the check engine code has been read, If you notice any fuel smell, Weather conditions when the problem occurs These details would help determine if your issue is identical to what I experienced with the clogged system.

Thanks for the responses. My Q2 has 69795 KM on the clock with the last service done 2 months ago. Since then, I noticed strange fuel smells and the purge valve seems to make clicking sounds when starting the car. The engine light started flashing only during wet weather. The error code P0441 was read at an auto parts store, pointing to the evaporative emission control system. The gas cap seems tight but the rubber seal looks slightly worn. I plan to get this checked professionally since tank ventilation issues can be tricky to diagnose correctly.

Based on the P0441 code and those symptoms, you are definitely dealing with a similar emission system issue as I had. The clicking purge valve sound and fuel smell are telltale signs that match my experience exactly. On my Q3, the worn gas cap seal was actually contributing to the problem, working together with the clogged ventilation hoses to throw off the system readings. The wet weather connection is interesting, had the same pattern on mine where the check engine light was more likely to appear during damp conditions. This often happens because moisture can affect the sensors in the evaporative emission control system. Would strongly suggest replacing both the gas cap seal and having the entire tank ventilation system inspected. In my case, just cleaning the hoses wasnt enough, we ended up replacing the purge valve too since it was making similar clicking sounds. The total repair came to about 220 Euro that time, but it completely resolved the stalling and warning lights. Quick tip from my experience: while waiting for the professional repair, try to keep the tank filled above 1/4 to reduce stress on the emission system. This helped reduce the frequency of stalling on mine until I could get it fixed properly.

The symptoms and advice match my situation perfectly. The connection between wet weather and system issues makes a lot of sense now. It is reassuring to hear a similar case was fixed without major expenses. My EVAP system definitely needs professional attention, especially with that faulty purge valve sound. The pressure sensor readings are probably affected by both the worn gas cap seal and potentially clogged ventilation hoses, just like in your case. Already scheduled an appointment with an automotive repair shop for next week. Will have them do a complete tank ventilation system inspection, replace the gas cap seal, and check the purge valve. The 220 Euro cost estimate seems reasonable for the needed work. Meanwhile, following your advice about keeping the fuel level above 1/4 tank. The stalling has already become less frequent since implementing this. Thanks for sharing your experience, it helped narrow down the exact issues to address.