Is it the catalytic converter or something else?

Hi Pete I have bought a hyundai getz 2 month ago and replaced a 3pc exhaust back box, middle silencer and front pipe. Although now the catalytic converter gets hot as soon as I start the car plus yesterday I was driving for roughly 30/40 minutes when I stopped there was lots of smoke coming from the catalytic converter so I had a look and there was water and steam (maybe condensation) coming from where the cat and the front pipe connect, I thought it would be the head gasket but there is no milky substance on the cap or anything do you know what the problem could be.

Regards.