Cat's pee starting to smell strong again

My male cat was neutered shortly after his first birthday. (we didn't feel the need to neuter him because he never sprayed) after his neutering, his pee didn't smell bad anymore. He was also a very hyper cat, but he calmed down a bit after he got neutered. Now, he just turned two last month and it's like he was never neutered! His pee stinks up the whole place and he's hyper as ever. I want to know if anyone has ever experienced this, and if so, what can I do about it? Thank you to anyone that can help!

My first stop would be at the vet's just to rule out anything medical. Then,  a lot of times the strength of the urine smell is related to the amount of water they take in.  If you're feeding canned food, try adding water to make the food about the consistency of oatmeal.  That way, he'll get more water in his body.  The longer they hold it, the stronger the smell, so increasing intake might help him eliminate more.