Hi guys wife's 1.5 sx 2006 if you put you foot down on accelerator it revs up fast over an additional 1000 revs to what you doing then comes back down. Does it in 3rd 4th and 5th tonight down motorway if you accelerate steadily its fine. Any ideas what it could be? Car seems fine idling etc no fault codes or no engine management light on. Thanks Daz