Just seen this on another forum - http://www.enginecarbonclean.com/ The service costs around £100. What it is, is disconnecting a vacuum hose from a hot engine and making the engine drink a pint of water, a trick as old as the internal combustion engine. They make it sound so scientific people will buy anything unrelated - I don't know what's wrong with the forum, but it's unbearably bad to try and use on my phone!