VW Eos Engine Stalling Linked to EVAP System Issues

I had a very similar issue with my 2014 VW Golf 2.0T last year, and having dealt with several basic repairs before, I knew this required professional diagnosis. The symptoms you describe match exactly what I experienced, rough idle, stalling, and check engine light. The workshop diagnosed a faulty activated charcoal filter in the EVAP system, which was causing emission control issues and irregular air flow through the system. The repair involved: Complete diagnosis of the EVAP system, Pressure sensor testing to confirm the issue, Replacement of the activated charcoal filter, System testing after replacement Total cost was 275€, including parts and labor. The fix completely resolved the stalling and rough idle issues. Before suggesting more specific solutions, could you share: Have you scanned for error codes? Does the problem occur more frequently when the fuel tank is near full? Do you notice any fuel smell, especially after filling up? Has there been any recent fuel system maintenance? These details would help confirm if your system failure matches what I experienced with the charcoal filter issue.

Just had my 84808km service last month. The issue started showing up right after. The workshop scanned for codes and got P0456 and P0441, both related to the EVAP system. The problem definitely gets worse when the tank is full, and there is a slight fuel smell after refueling. The purge valve was replaced during routine maintenance about 2 years ago. An interesting update: the check engine light started flashing occasionally yesterday, particularly during idle. The engine stalling seems more frequent in the morning when the engine is cold. No recent fuel system maintenance beyond regular fuel filter changes during scheduled service intervals. The fuel efficiency has also dropped noticeably in the past weeks, from around 7.5L/100km to nearly 9L/100km.

Thanks for those additional details, they really help confirm what we're dealing with here. Those P0456 and P0441 codes are exactly what I saw with my VW when the charcoal filter failed. The flashing check engine light and increased fuel consumption match my experience too. The timing after your service is interesting, on my car, the issue became noticeable after routine maintenance as well. The workshop explained that sometimes handling the EVAP system components during service can accelerate existing wear or reveal developing problems. In my case, the morning cold-start issues were directly linked to the faulty charcoal filter not properly managing fuel vapors overnight. The system failure was causing vapor leaks, which explains both the fuel smell and the efficiency drop you're experiencing. Since your purge valve is relatively new, I'd strongly suggest having the charcoal filter and its surrounding seals checked first. The emission control system is sensitive, and even small leaks can cause these symptoms. When my filter was replaced, the technician also found deteriorated seals around the pressure sensor connections. My repair ended up being straightforward once properly diagnosed, just make sure they pressure test the entire EVAP system after replacement to ensure there are no remaining leaks.

Based on your description and findings, I will get the charcoal filter and seals checked right away. The symptoms you experienced match mine exactly, especially the cold-start issues and fuel smell. Your insight about maintenance possibly triggering latent problems makes sense, since this started right after my service. The declining fuel efficiency and those specific error codes really point toward the charcoal filter being the culprit. Since my purge valve is still relatively new, focusing on the filter and seals seems like the logical next step. I will insist on a complete pressure test of the emission control system after any repairs. I will contact my workshop tomorrow to schedule the diagnostic work, specifically mentioning the charcoal filter and surrounding seals. The full tank correlation and morning stalling issues definitely support this being an EVAP system problem rather than something more serious with the engine itself. Thank you for sharing your experience, it has helped narrow down the likely cause and saved me from potentially exploring more costly repairs first. I will update once the repair is complete to confirm if the charcoal filter replacement resolves all these symptoms.

I had my 2012 VW EOS serviced around May 25th for oil change, light bulb replacements & maintenance on the convertible mechanisms. We went to the beach for a week right after that & it has just been driven normally since. Last week I was running errands & the engine light came on out of nowhere. It is not driving “hard” or “rough”. It’s not idling any different from what I can tell. I haven’t seen anything leaking from under the car, just nothing. I did just fill my tank up the day before the light came on. Also, a couple of month back the rubber piece that holds the gas cap in place (so it doesn’t just fall to the ground) broke off. Could that be the culprit? She goes to my mechanic on Monday but I’ve been super worried since that light came on. I have not driven the car since the light came on. I drove it straight home & parked it. Thanks for any help

It's good that you're taking the car to your mechanic soon. The check engine light can be triggered by a variety of issues, and since you mentioned the gas cap, it's worth checking if it's properly tightened. A loose or damaged gas cap can cause the light to come on due to a small leak in the EVAP system. Make sure the cap is secure and see if the light turns off after a few drives. If the light remains on, your mechanic will be able to scan for error codes to pinpoint the issue. Let me know how it goes after your visit to the mechanic, and feel free to ask if you have more questions.