Lexus IS Diesel MAF Sensor Symptoms

Hey, I had almost the exact same symptoms on my IS: higher fuel consumption, stalling, and that check engine light. It does sound like the mass air flow (MAF) sensor. Have you tried cleaning it? Sometimes that helps, but if it's genuinely defective, cleaning won't do much. Do you have access to an OBD2 scanner? That would confirm the MAF sensor issue.

Thanks for the quick reply! No, I haven't tried cleaning it yet; I am not sure how to do that. I don't have an OBD2 scanner either. Is it easy to clean the MAF sensor, and could a faulty MAF sensor really cause all those problems at once?

Cleaning it involves removing the sensor and using a special MAF sensor cleaner – you can find guides online. But honestly, based on your symptoms, especially the stalling and smoke, I'd lean towards replacement. A defective MAF sensor messes with the air-fuel ratio, which explains the poor fuel economy, stalling, and even the smoke from unburnt fuel. I'd advise taking it to a reputable mechanic; they can properly diagnose it and confirm if it's the MAF. It could save you time and potential headaches.

Thanks a lot for the advice! I took your suggestion and brought it to my mechanic. They confirmed it was indeed the MAF sensor and replaced it. Cost me about 365€, but now it runs like a charm! No more stalling, the check engine light is gone, and the fuel consumption is back to normal. I really appreciate your help!