Hi have an Audi A4 170. It's been remapped because of a filter fault. I am now experiencing white smoke from the exhaust when idling, and a strong smell of unburnt fuel? I think that's what the smell is. I seem to be chucking money lately at it , i even had a diagnostic on the car but they coudlnt find anything.  People that I ask keep saying it could be injectors but the were replaced a couple of years ago. A friend is now saying it could be a EGR valve. Has any body come across this problem before?  Thanks.  One very frustrated audi driver.

Hi Karl...welcome to the Forum

Is the car predominantly driven around town or is it worked on long or fast journeys?

Only, if it's smoked around town it leads to carbon build up in components such as EGR, injectors, piston rings...all of which can lead to the symptoms you describe.

Running fuel additives to clean the engine and a good blast to clear it through may sort it.

Let us know how this progresses.

Cheers  Trevor