I have two cats about 10 months old. I changed litterbox and litter around Christmas and within 2 weeks it became evident that they did not like the new litterbox situation, as they had pooped on the floor by the litterbox and had peed on the couch. I changed the litterbox back as well as got a second litter box to give them more space.
They stopped pooping on the floor; however, every once in a while (maybe once a week) they will pee on the couch, always in the same spot. The couch still has a slight smell despite using cleaner and I am planning to replace it, but I'm worried they will pee on the new couch. They aren't acting any different otherwise to indicate a medical issue and they are using the litter box (for pee and poop). This feels like a learned behavior that they picked up when they didn't like the litter box.
If I get the new couch and it doesn't smell, would they pee on it or are there any other things I can do to stop them from peeing? I was considering putting things on the couch to make it uncomfortable for them to stop them from peeing on it. Also I haven't been able to determine if it's both cats or just one cat peeing on the couch.