Audi S5 EVAP Failure Causes Stalling at Low Miles

Had similar issues on my 2015 Audi S4. The symptoms matched exactly, check engine light and rough idling. The purge valve in the emission system was malfunctioning, and several ventilation hoses connecting to the fuel tank were completely clogged. The pressure sensor was also giving false readings due to the blockage. This turned into a serious repair as the clogged system caused excess pressure in the fuel tank. If left unchecked, it could have led to fuel delivery problems and potential damage to other components. The fix required replacing the purge valve, cleaning the entire EVAP system, and installing new ventilation hoses. Common issue with these models, the gas cap seal can also contribute to similar symptoms by not maintaining proper tank pressure. Worth having the entire emission system checked by an Audi specialist who knows these specific models. Previous poor service could have introduced contamination into the ventilation system. Based on your low mileage, this definitely warrants professional diagnosis at a different shop with Audi certification. These symptoms rarely resolve on their own and typically indicate a developing issue in the EVAP system.

Thanks for sharing your experience. This really helped as I was worried I might need a complete fuel system overhaul. Would you mind sharing what the total repair cost was in your case? Also curious if youve had any related issues pop up since getting it fixed. My main concern is making sure this doesnt become a recurring problem with the purge valve or tank ventilation system.

After getting it properly diagnosed and fixed at a certified shop, I can report no recurring issues with the emission system. The repair focused mainly on cleaning out the clogged ventilation hoses connected to the fuel tank, which cost 175 Euro. This was much more reasonable than I initially feared. The purge valve and EVAP system have worked flawlessly since the repair, no check engine lights or rough idling problems. The key was catching it early before the clogged hoses could cause more extensive damage to the fuel tank ventilation system. Regular maintenance at a qualified shop should prevent similar issues from developing again. A properly functioning ventilation system is critical for maintaining correct fuel tank pressure and preventing emission system problems.

I took your advice and brought my S5 to a certified Audi specialist. The diagnosis confirmed exactly what you mentioned, clogged ventilation hoses and a faulty purge valve in the EVAP system. Total repair came to 320 Euro, which included a thorough cleaning of the emission system and replacement parts. The mechanic found evidence that the previous shop had used incorrect cleaning products, which left residue in the tank ventilation system. Since the repair last month, the check engine light has stayed off and the idle is perfectly smooth. No more stalling issues. Really glad I caught this early. The specialist mentioned that waiting longer could have led to more expensive fuel system repairs down the line. The car runs like new again, and now I know to pay closer attention to the EVAP system during routine maintenance.