VW Up Stalling & Engine Light: EVAP System Troubles

Had similar symptoms on a VW Polo 1.2 TSI from 2017. The stalling was caused by a failing activated charcoal filter in the EVAP system, affecting overall fuel efficiency and engine performance. The purge valve and charcoal filter were both compromised, allowing excess fuel vapors to enter the intake system at idle. This created an overly rich mixture, leading to rough idling and stalling. The leak detection pump also showed faults during diagnosis. The fix required replacing the complete charcoal canister assembly and purge valve to restore proper air flow and vapor management. Not a critical safety issue, but leaving it unfixed can damage other components and increase emissions over time. Main symptoms that matched: Stalling specifically at idle, Check engine light, Rough running after cold start, Inconsistent idle speed Best to have it checked soon, as these EVAP system issues tend to worsen and can affect other engine management components if left unaddressed.

Thanks for sharing your experience. This sounds exactly like what I am dealing with, including the rough running after startup. Just had my VW Up in for a basic service and wish they had caught this earlier. Were you happy with the repair work and has everything been running smoothly since? Would really help to know what kind of repair cost I should expect. The parts seem quite specific, and I want to avoid getting overcharged. The fuel efficiency has definitely gotten worse lately, which makes sense given what you described about the fuel vapor issues. Hope it will improve once fixed.

Got my VW back from the mechanic last week and can confirm the fuel tank ventilation system leak was resolved. They diagnosed and replaced the defective activated charcoal filter, which cost 275€ total including labor. The air flow and engine performance have significantly improved since the repair. No more stalling issues at idle and the system failure warnings have completely disappeared. The biggest improvement has been in fuel efficiency, back to normal consumption levels now that the vapor management is working properly. The leak detection system is functioning correctly, and the check engine light has stayed off. Would definitely recommend getting it fixed soon, as the repair cost is reasonable compared to potential long-term damage to other engine components. Just make sure they specifically check the charcoal filter and purge valve during diagnosis, as these are the common failure points in these systems.

Thanks for the advice. Got my car fixed yesterday and wanted to share the outcome. Took it to a certified VW shop and they confirmed the EVAP system fault through proper diagnostics. The charcoal canister was indeed shot and letting fuel vapors mess with the air flow. Total repair came to 310€ including a new purge valve, which they recommended replacing while they were in there. The difference is remarkable, no more stalling, steady idle, and the check engine light is gone. Fuel efficiency has already noticeably improved after just a few days of driving. The repair cost was in line with what others mentioned, so I feel good about not getting overcharged. Best decision was getting it fixed promptly before it could cause more issues. The whole process was straightforward once I found a reliable shop that knew what to look for. Really appreciate all the helpful insights that pointed me in the right direction.