Hello: I have a brand new Yaris, liftback, automatic. The first day I had it, I noticed this problem (I did not notice is during the test drive) and I need to know if this is normal or do I have a car with a problem. When I take my foot off the gas, the engine sometimes slows down jarringly, like the car just hit a patch of wet sand. And sometimes it even feels like it surges back to normal again. This doesn't happen all the time when I take my foot off the accelerator but I notice it the most when I am in stop and go traffic and accelerate a little then take my foot off the accelerator. Sometimes I even feel it when I still have my foot on the accelerator but not giving it much gas. Like the engine surges down quickly and sometimes even back up again. I hope I am explaining this right. I haven't had a new car in 10 years so maybe this is normal? I want to use the term engine braking but I really am not sure if that is what it is doing. Can anyone tell me if they have this similar feeling? I am going to try to go out this weekend to drive other Yaris's to see if this is just how they drive. Anyone? Thanks so much! This is really bothering me.