I have a problem with my 2005 C220 which results in a puff of black smoke on initial acceleration. Once up to speed there is no/very little smoke. I've had the car for 6 months. The person before me had a remap (which I know can cause overfueling thus black smoke) but I hadn't noticed it until recently. Here's what I've tried/checked so far: New air filter Checked for any air leaks in intake/turbo hoses/intercooler Run Redex diesel in a tank of fuel I don't use supermarket fuel Checked for visible and audible sounds of injector leak - nothing found Taken the car on a good run on the motorway - no change I presume there is an overfuel or one of the injectors isn't operating correctly. Could anyone give me any advice on where to look next before I start getting into the expensive world of replacing injectors? TIA.