My 5 month old pup was doing quite well at first on the pads & litter box. I ususally scoop out his poop immediately and change his litter box every week. Now that it is warmer, I take him out for walks when I get home in the evening. The problem that I am having is, my pup will pee on the floor and poop in his litter box. I am constantly disinfecting my floor to try and stop him from doing that. Please give me some idea of what I can do to help my pup understand not to keep peeing on the floor, but in his litter box. I have gone back to placing him in his crate.
You need to catch the puppy in the act and tell him "no" and then put him in his litter box, just gotta do that over and over till he gets it again. Is it carpeted where he has been peeing or tile? Sometimes they just forget or get confused, he needs to be reminded over and over...
From your post, it sounds like you were just leaving the dog out with it'slitterbox while you were at work during the day? At 5 months most dogs aren't fully reliable.. I wouldn't let mine have free run yet. If you can't be there to help correct peeing in inapropriate places, you are backsliding on housetraining, because no one is there to say oops please pee here instead.
Are you cleaning the floor with a cleaner that is formulated to get rid of pet stains/smells? That way the scent of the pee/poo is gone not only to you, but also to him & he won't want to pee in that spot anymore. I would still cage him while you are away until you are sure he will use the paper/pads consistently, or that he can hold it until you get home.
I don't have much knowledge about Chihuahua puppies but I have had other breeds. If you're cleaning the floor with household cleaners - stop. Most have ammonia or other ingredients which will smell like old urine. You need to use a cleaner designed to eliminate pet odors. I found that Simple Solution worked the best for my floor and carpet when my Sibes were younger, but we didn't get rid of the puppy pads until they were all about 11 months old..