My 2014 Accord Sport CVT had a problem with the transmission slipping when it was cold. I took it to Honda and they did something with the trans and a software update, this was around 5 months ago. I have noticed that the mpg has been falling a lot and the other day I noticed where the car was losing all the gas, when I was idling. I was at a traffic light and in one minute I lost two tenths of a mile. My wife was idling the car and in around 45 minutes the mpg went from around 20 mpg to 10 mpg. My question is could the software update contribute to this? The thing that puzzles me is the car Idles fine at around 800 rpms.

 

Sounds totally normal to me; why do you think this is an issue?