Thank you all for your help, truly appreciate it. So basically I went to the vet and it was not a UTI. The DR. found no inflammation and no infection. He says that it's mostly psychological and the trip to the salon may have most likely traumatized him. Now I'm trying my best to get him back to peeing on his mat. I guess no more salons for him I need to learn to do it myself and honestly that's what I truly recommend for everyone. The DR mentioned how yorkies tend to be very sensitive so someone may hurt them mentally without even knowing it, he told me to keep an eye on that. On the bright side little Coco is healthy which I'm very happy about. Thank you all
-Maria