indeed the engine will rev up 500rpm from time to time. I'd say 80% of the time it's between gear shifting, particularly annoying when down shifting and that the car accelerates by itself.
It took me a while to figure that out (I thought also it was only during hot/humid days) ... the problem only appears when the A/C is on (during hot/humid day of course, but also to remove the haze on the windshield). The car has been in the 2 different dealers (the first one couldn't even see the problem after repeated visits among other things ), the second one told me that the computer couldn't find anything, that SVT engines are purposely tuned like that for the American drivers and that I'm not used to it, being French ... I could understand a special tuning, I can't agree however that this is a normal behavior, a car should NOT accelerate by itself for any reason in the world.
Anyway ... they had to change the catalytic converter (39k miles only), hopefully that's one of the 2 things Ford fully cover until 80k miles apparently.
I did 1-2 try with the A/C on and didn't feel the problem anymore, will see in the long run
