I love my new Subaru but occasionally the acceleration feels stuttery, it's not smooth. Usually on the first acceleration of the day. I am careful not to push hard when the engine is cold and the blue light it on.

Sometimes when cruising at say 70 mph it does what feels like a missed beat, like a small blip.

I went to the garage I bought it from and they weren’t that interested as it didn’t do it when they drove it and they gave me the impression that I was wasting their time!

They said as there are no warning lights come on they can’t locate the problem! It has done 13500 miles and was serviced by them just before I bought it in April.

As a layman I would say it feels like the fuel is momentarily not getting through but a friend says it maybe the O2 sensor... any ideas please?