IS220d - 108k
4 months ago the engine management light came on along with the traction control - did not go into limp mode but mpg down to 34mpg from 40mpg
Got some Wynne Extreme Diesel Clean and filled up with Shell V power - seemed to do the trick with a good blast and all lights went out. MPG crept up to 37mpg. However I did have an intermittent problem with White smoke pouring out of the exhaust once the engine was up to temperature - after around 40 miles travelling. Thought the dpf was going into regen so would give the car a good blast if the road conditions were right , whenever this white smoke appeared. Did not do anything else about it....
Last week lights came back on , and this time no power whatsoever, car would not go over 40mph. Just the same engine management light and traction control. Called the dpf doctor and for £240 the lights are off and power restored. He said the dpf filter was blocked. For a few days after the White Smoke was pretty bad - again when engine was warm . I disconnected the battery overnight and White smoke does seem to have gone - MPG up to 38mpg - car running ok but not at its best I don't think.
Need the car to last another 12 months so looking at other investigations I can carry out to look for any underlying problems - oil and coolant levels always been ok.
Any tips appreciated