VW Eos: Engine Stalls & Poor MPG Point to MAF Sensor

Had almost the exact same issue with my 2012 VW Golf. The symptoms you describe match what I experienced, poor fuel economy, stalling, and the exhaust smoke all point toward air-fuel ratio problems. After some initial troubleshooting, my workshop confirmed it was a failed mass air flow sensor. The sensor was no longer accurately measuring the air intake, causing incorrect air-fuel mixture calculations. The repair was straightforward, total cost was 365€ including: New MAF sensor, Diagnostic check, Labor, Replacement air filter (they recommended this while doing the work) After the fix, fuel economy improved significantly and all other symptoms disappeared. The entire repair took about 2 hours. Before you proceed, could you share: Current mileage on your Eos? When was your last air filter change? Are you noticing any rough idling or hesitation during acceleration? Have you scanned for specific error codes? This information would help determine if your issue is indeed sensor failure or potentially something else in the air intake system.

Last service was done 3 months ago where they replaced several fluids, but no air filter change was performed. The symptoms you describe are identical to mine. I also had the mechanic scan the codes which showed a P0101 error related to the mass air flow sensor readings. Since my mileage is at 133716km, I am wondering if this could indeed be a combination of a dirty air filter and faulty MAF sensor affecting the air intake system. The symptoms have gradually worsened over the past month, especially the decline in fuel economy. Does testing or cleaning the MAF sensor make sense before full replacement? My local parts store quoted 295€ for just the sensor.

The P0101 code definitely strengthens the MAF sensor diagnosis. During my repair experience with the Golf, I first tried cleaning the MAF sensor, it worked temporarily but the issues returned within a week. The combined high mileage and dirty air filter likely contributed to the sensor failure. While cleaning the MAF sensor is possible using specialized cleaner, my experience shows its often just a temporary fix when the sensor is actually failing. Given your mileage and symptoms match my situation almost exactly, I would recommend: 1. Replace the air filter first, its the cheaper fix at around 30€ 2. Install a new MAF sensor rather than cleaning the old one 3. Have the entire air intake system checked for leaks during installation That 295€ quote for the sensor is actually reasonable, I paid slightly more at 310€ for just the part. Make sure to get a quality OEM sensor though, as aftermarket versions can be unreliable. The combination of a fresh air filter and new MAF sensor should resolve your fuel economy issues and prevent further engine performance problems. Just ensure whoever does the work clears the error codes after installation. Would you like details about the specific cleaning procedure? Though I ultimately needed replacement, the cleaning process might help others reading this thread.

Thanks for the detailed information. Based on everything you shared, I will move forward with replacing both the air filter and MAF sensor. The gradual worsening of symptoms and the P0101 error code really confirm what you experienced. I think attempting to clean the sensor would just delay the inevitable given my high mileage. The poor fuel economy and engine performance issues are too significant to risk a temporary fix. I will ensure to use an OEM sensor despite the higher cost of 295€, as reliability is crucial. Will schedule the repair next week and make sure they check the entire air intake system during installation as you suggested. The combined symptoms of stalling, smoke, and efficiency loss match your case too closely to ignore. Once everything is fixed, I will report back on the results for others who might face similar sensor failure issues in the future. One quick question though: How long did your fuel economy take to return to normal after the repair was completed?