Help with my cat peeing in my floor?

my cat is 10 years old this year and he still acts like a kitten. however i moved out of my parents house 2 years ago and i took him with me because he was always my cat. in our 1st apartment he developed this problem where he peed under or dinning room table not in the litter box. we thought it was a behavior problem took him to specialist literally spent a ton of money trying to figure it out. even took him to the vet a few times his health checked out clean. got a second opinion same story. it wasn't the move ether he adjusted very well as he is used to going strange places. we didn't know what to do we moved to the apartment to where we live now and he stared doing the same thing we thought it was the table so we got rid of it and i cleaned the carpet really well. he still does it. i need help i bought him the same litter box he had at home to help he even has a lot of privacy as the litter box in in my walk in pantry. still he pees out in our dining room and i think he has peed in the living room too. i have to figure something out can some one help me tell me what i can do to make him stop or i will have to give him away. we rent so we will have to replace carpet if he doesn't stop. we already had to pay over 1000 dollars to our old apartment to replace carpet. i just don't understand why he developed this problem. i feel exhausted i have to go behind him with the resolve every couple hours. i want to keep him just don't know what to do but it has to stop. some one with experince with this please help. o and it's not marking he is the only cat.