Head Gasket

All internal combustion engines have water in the exhaust. It is a byproduct of combustion. He black is soot from the pipe that comes out with the water. You don’t see the water on catalytic converter equipped cars.

Do you have stock exhaust manifolds? Does the heat riser work? If so then its blocking the right side and all the cold engine exhaust comes out the left side pipe.

Why is it a head gasket is you never have to add coolant?

You will change head gaskets for nothing and it will still do the same thing.