Thanks John
What/where is the EHC unit, car is starting fine then runs like a bag of spanners with black smoke as soon as the car warms up, not the famous fuse behind the battery I've checked. local dealer reckons that the system that helps for the first few seconds of warm up may not be shutting down so car running way too rich ( explaining the sooty plugs) would like to disconnect this to see if it makes a difference before throwing money at it