hi igota bad fueling prob on my saff coz thet bad it nackers plugs on tick over and throws out so much smoke blue black grey it unreal guzzler has told me to check ecu and sensors so can anyone tell me in detail coz im thick how to test a coolant sensor with a multimeter i.e wat setting to use on the meter and is it easier to test the sensor off the car with hot water and wat should the reading be

cheers jay