Hi all. 2015 fit here with 115k miles. I've owned it since new. Do all my own maintenance. About a month or so ago I noticed a pretty big drop in mpg. Usually around 38-40 down to 30-32. But the car still seemed to be running mostly ok. Idle was a little rough but not terrible. I have a cheap scan tool and when I hooked it up my long term fuel trim was running lean by about 15%. Not enough to throw a cel....

Ran through a bottle of techron and noticed no improvement. After some other research I tried cleaning the maf sensor. No improvement. Since a replacement denso was only $70 on Amazon I thought what the hell. Id.give this a shot before messing with the O2 sensor. And sure enough it fixed the issue. My maf sensor was sending bad readings. Idle is now perfect again, 0% LT fuel trim, and mpgs back to normal. Just thought I'd post this as a FYI, bad maf seemed to drastically effect the fits mpg.

 

Thanks for the heads up!

 

I've noticed my MPG dropping (98K miles) on my 2016 a tiny bit. I didn't think to use my scan tool. Thank you for posting. I'm going to check it out later.

I'm usually around 38+ consistently and noticed I'm down to 35 with my idle being a little off at times but no CEL. I was thinking spark plugs (since it's almost time to change them).

Steve

 

@Tslipknotm6 Thanks for sharing that information. Thinking about others once in a while is what makes this community.