Exacty, the O ring was the problem. But think of this. Lets say we had an external tank filled with water. No chance of explosion, right? Thats my point, we need to use a "safe" fuel and split it as the demand requires. So if there is any expolosion, it will be the small amount of gaseous fuel held in the fuel line between the electrolizer and the intake manifold. How much can that be, in my case maybe a beer cans worth? It would make a hell of a pop, but thats it.