VW Virtus Stalling: Failed EVAP Check Needs Second Look

Had similar symptoms with a 2015 VW Polo TSI. The fuel efficiency dropped significantly and engine stalled frequently at idle. Despite initial checks suggesting the purge valve was working, further diagnosis revealed a defective activated charcoal filter in the EVAP system. The leak detection pump and pressure sensor were reporting system failure due to the deteriorated charcoal filter. This component prevents fuel vapors from escaping into the atmosphere while storing them for later combustion. When it fails, it disrupts proper vapor flow management. The fix required replacing the complete charcoal canister assembly. This was not a quick repair since accessing the component meant dropping the fuel tank partially. The system needed proper vacuum testing after installation to ensure no leaks remained. While not immediately dangerous to drive, continuing with a faulty charcoal filter can lead to: Increased emissions, Failed emissions tests, Poor fuel efficiency, Persistent check engine light, Possible damage to other EVAP components Recommend getting the entire EVAP system tested, focusing on the charcoal filter and associated components. A proper smoke test can identify exact leak points in the system.

Thanks for sharing this detailed insight. My symptoms match exactly what you described with the stalling and efficiency issues. Planning to get the charcoal filter checked out this week. Could you remember roughly how much you paid for the complete repair? Also wondering if you had any recurring problems with the EVAP system or air flow after fixing the charcoal canister?

Finally got the repair done last week and it fixed all issues. Like in my case, the emission control system was compromised by a bad charcoal filter. The total cost came to 275€, which included the new filter and labor for accessing the fuel tank area. Since the repair, the engine runs smoothly with no stalling. The leak detection system shows no more faults and fuel efficiency is back to normal. The check engine light has stayed off, confirming the EVAP system is working properly now. No recurring problems at all with air flow or emission control components. The purge valve and pressure sensor are both functioning as they should. This repair truly solved all the symptoms that were troubling the car before. The mechanic mentioned these charcoal filters typically last 60000-80000km when working normally, so you should be good for quite a while once replaced. Just make sure they perform a complete system test after installation to verify there are no remaining leaks in the setup.

Thanks for the input. I took my car to the mechanic yesterday based on these suggestions. They confirmed the charcoal filter was indeed the culprit. The repair cost me 290€ but worth every cent. The process took about 3 hours since they had to partially remove the fuel tank to access the canister. They ran a full pressure sensor check after installing the new filter and found no other issues in the EVAP system. Started the car this morning and what a difference, no more stalling, engine runs smooth, and the check engine light is finally off. The air flow seems much better and the engine feels more responsive. Really glad I got this fixed before it caused any system failure or more serious problems. Would definitely recommend anyone with similar symptoms to get their charcoal filter checked right away. Better to catch these issues early than wait until there is major trouble with the emissions control system.