Our Maine Coon Luca loves to poop outside the cat litter box even when it is clean which we make a point of doing since we know how picky he is! So know he finally has been shamed because he obviously thinks outside the litter box is better than in.
Let me poop where I wanna!
If your cat is declawed then the problem could be the litter. If the granules are too big they get stuck in his paws where the claws usually are. Try switching to a finer litter.