Highlander MAF Sensor Issue

Sounds like you might have a MAF (Mass Air Flow) sensor issue. I had similar symptoms with my Highlander – higher fuel consumption, rough idle, and eventually the check engine light. Your air-fuel ratio is probably off, which explains the smoke and the poor performance. It's like trying to breathe through a straw while running a marathon. Is the performance really bad?

Okay, MAF sensor. If it is the MAF sensor, what did you do to fix it? Did you try cleaning it or just replace it? And how bad was 'bad' performance for you? I mean, mine is definitely sluggish, but I can still drive it.

I didn't risk damaging the sensor further, so I took it straight to the workshop. They confirmed it was the MAF sensor after running diagnostics. Trying to clean it could make it worse! You should have it checked out by a professional because if the LMM is defective, you will have to change it anyway.

Thanks, that's helpful. I took it to my mechanic, and you were right – it was the MAF sensor. They replaced it, and the total cost was around 365€. Fuel economy is back to normal, no more stalling, and the check engine light is gone. Thanks again!