ciccio ske

hello i have a problem to my GC8 v6 2000. ECU mount gems when I turn the key on the machine contact is a blast as if from the current to the spark plugs and burning gasoline in the cylinders without having still on. and the second problem does not take the least in practice is switched on a few seconds later I see that the wideband smagrisce alone until it turns off. someone can help me?