Potty training dog

I need some advice on potty training my dog. I have never had this much trouble for this long with getting a dog trained. He is a Pug and I read that they were stubborn, but boy am I finding out just how stubborn! We got him as a puppy and started him out on pee pads and he did well up until a couple of months ago. He is now nearly a year old and just going where he feels like it. He is so hard to catch in the act!

If we confine him to one room, it goes one of two ways: He will pee in one spot, (on the Wiz Dog) or he will hold it for as long as he has to until he gets let out of that room. I don't know if he is confused or what?!? It was just kind of a strange turn from perfect dog peeing where he was supposed to to bad dog going everywhere and anywhere. I am especially worried about pet stains and smells! I have been able to keep that part under control for now at least.

This is really frustrating! What can I do??