Update
So i decided to change the fuel filters on it over the weekend at a local service depot..all was fine until i cranked up the engine and gave it some gas...the engine kept stalling and blowing white smoke from the pipes..it has a very slight rough idle but apart from that engine runs fine on idle...the guy at the depot reckon i have water in the lines which is causing this..but it ran fine until i changed the filter so i dont think that was the problem..in the end towed it back home but im scratching my head wondering where to start..
My d40 did that after I removed the air sensor in the air box.
Did an ecu reset and it fixed it....