Dandy. Throw a fuel pressure gauge on it. If an injector is stuck, which is extremely rare, the pressure will drop as soon as the engine is turned off. It will also have an unusually-long crank time to get it started, and that leaking fuel will show up in the engine oil.
White smoke is a sign of burning engine coolant, typically from a leaking cylinder head gasket, but GM has had a lot of trouble with intake manifold leaks. I would look there first if the level is dropping in the coolant reservoir.
Also, be aware that water vapor is one of the byproducts of a properly-working catalytic converter. There can often be water dripping from the tail pipe or the drain hole at the back of the muffler. The clue that it is normal is the puddles will be clear, not green or red.
Monday, February 27th, 2017 AT 1:42 AM