i understand that the diy diagnosis tools around today are a cost efective way to maintain and repair a car. do they have to be make specific, can you turn off the service light and how good are they? how much do they cost aprox? i am looking to service and light repair my 08 zafira untill such time that it goes to that great scrap yard in the sky. it's a 1.8 ecotech by the way.