You don't say what kind of training you are using, so it's hard to comment. If you look in the Files section of the group's homepage, I've uploaded a file called housebreaking.txt. It's the technique I used to train my chihuahuas to use pee pads, but it will also work with other forms of potty training.
Please, you should NOT be considering giving your chihuahua up at this stage. At three months of age, that puppy is barely old enough to be away from his mother -- chihuahua puppies should NOT be taken from their mothers until 12 weeks (three months) of age. Your puppy is too young to have good control of his bladder. If you have been yelling at your puppy or otherwise disciplining him, it's probably going to take longer now to potty train him because he may now be fearful to potty with you watching him. Please read the file, give positive reinforcement a try, find a non-carpeted room such as a bathroom where he can be baby gated in when you can't be watching him closely, and please, please, be patient. Your puppy is still just an infant. He is not doing this maliciously or because he's stupid. Anne
