MAF Sensor Issues Cause Engine Stalls and Poor MPG

I dealt with nearly identical issues on my 2016 Buick Enclave. As someone with some experience working on cars, I first tried cleaning the mass air flow sensor, but the problems persisted. The symptoms matched yours exactly: Poor fuel economy, Check engine light, Performance decline, Rough idle and stalling, Exhaust smoke under acceleration The root cause was a faulty mass air flow sensor affecting the air-fuel ratio. After the cleaning attempt, I took it to a repair shop where they confirmed the sensor was defective and needed replacement. The repair cost me 365 Euro including parts and labor. The difference was immediate after replacement: Smooth idle returned, Better acceleration, Normal fuel consumption, No more smoke, Check engine light cleared Before offering more specific advice, could you share: Have you scanned for error codes? When was your last air filter change? Does the problem get worse during wet weather? Have you tried cleaning the sensor yourself?

Latest service was at 98000 KM and thanks for sharing your experience. I pulled the error codes just now and got P0101 and P0171, which seem to confirm the mass air flow sensor theory. I havent touched the sensor yet since I wanted to get some feedback first from others who dealt with this. The air filter was changed about 3000 KM ago, and yes, the engine stalling and performance decline definitely get worse in damp conditions. The poor fuel economy is really hitting my wallet hard, so Im leaning towards trying to clean the sensor myself first before considering full replacement. The shop quoted me significantly more than what you paid for the repair.

Thanks for those details. Those error codes P0101 and P0171 definitely point to an air flow measurement issue, just like I experienced with my Enclave. The fact that your symptoms worsen in damp conditions is another classic sign of sensor failure. Since your air filter is relatively new, that rules out a clogged filter causing false readings. In my case, I also tried cleaning first to save money, using a proper MAF sensor cleaner spray. While it helped briefly, the issues came back within a week. The temporary improvement actually helped confirm the sensor was the problem. From my experience and the matching symptoms, you are likely facing the same failed sensor issue I had. The significant performance decline and high fuel consumption you are experiencing are textbook signs. If you want to try cleaning first, just be aware you might end up needing replacement anyway. A few tips if you try cleaning: Use only proper MAF sensor cleaner, Do not touch the sensor element, Let it dry completely before reinstalling, Clear the check engine codes after Would be interested to hear if cleaning helps or if you end up needing replacement like I did.

Those MAF sensor codes really helped confirm what I was dealing with. After gathering all this feedback and considering the symptoms match so closely with your experience, I decided to try cleaning the sensor first since the shop quote was pretty steep. Used proper MAF cleaner and followed your tips carefully, especially about not touching the sensor element and letting it dry completely. Unfortunately the cleaning only helped for about 5 days before the engine stalling and poor fuel economy issues started coming back. The damp weather made it especially bad again. Going to bite the bullet and get the sensor replaced since the air-fuel ratio issues are just killing my fuel costs anyway. Will probably shop around for a better price than my first quote though. Really appreciate everyone sharing their experiences and advice. Having others confirm the same symptoms and sensor failure patterns made me feel more confident about the diagnosis and repair path forward. Will update once I get the replacement done.