A3 Purge Valve Failure Causes Engine Stalling at Idle

Had the same symptoms with my 2016 Audi A4 2.0T. The check engine light and stalling were indeed linked to the emission system, specifically the tank ventilation components. The fuel tank pressure sensor was showing incorrect readings due to clogged vapor lines and a stuck purge valve. The repair involved cleaning the entire evaporative emission system and replacing several components. The main issue was carbon buildup in the hoses that connect to the gas cap and tank ventilation system. When these get clogged, the fuel tank cant properly vent, causing the engine management system to get confused about fuel pressure readings. This is actually a serious issue that needs prompt attention, as continued driving could damage other components in the fuel delivery system. The symptoms typically start mild but get progressively worse. The automotive repair process required specialized diagnostic equipment to properly test the entire evap system and identify all affected components. Getting it fixed early prevents more extensive damage to the emission control system. Worth noting that proper fuel cap tightening after refueling and regular fuel system cleaning services can help prevent these issues from developing.

Thanks for sharing your experience with the emission system issues. Your symptoms match exactly what I experienced with my A3. The check engine warnings started showing up out of nowhere at first, then became more frequent until the stalling got really problematic. Just curious, do you remember roughly how much you ended up paying for the full repair? Also, has everything been running smoothly since the fix, or have you noticed any other fuel system or tank ventilation related problems? In my case, I want to make sure I budget correctly and know what to expect when I take it to the shop, especially since these pressure sensor and purge valve repairs can vary quite a bit in cost.

Yes, can confirm everything has been running perfectly since the repair. The mechanic found several clogged hoses in the tank ventilation system that were causing the pressure sensor to malfunction. The total repair cost came to 175 Euro, which covered cleaning and replacing the affected components. The check engine light has stayed off and the idle stalling issue completely disappeared after they fixed the emission system problems. Going on 6 months now without any fuel system or tank ventilation related issues. The engine runs much smoother, especially at idle. Getting it fixed early was definitely the right call, clogged ventilation hoses can lead to more expensive repairs if left unchecked. The gas cap now seals properly and the whole fuel system vents as it should. No more pressure buildup or sensor warnings.

I finally got my car fixed last week and wanted to share my experience. The automotive repair shop confirmed it was indeed the tank ventilation system causing the problems. They found a faulty pressure sensor and several blocked lines in the emission system. The total repair came to 320 Euro, which included replacing the purge valve, cleaning the entire fuel tank ventilation system, and replacing two corroded hoses. More expensive than I hoped, but less than I feared. The repair took about 4 hours, and the difference is noticeable. No more check engine light, and the idle is perfectly smooth now. The fuel tank pressure is reading correctly, and the entire system is working as designed. The mechanic showed me the old parts, the purge valve was completely stuck and the ventilation lines were badly clogged with carbon deposits. They also gave me some tips about regular maintenance to prevent future issues with the emission system. Really glad I got this sorted before it caused more extensive damage. Thanks again for the helpful advice that pointed me in the right direction.