I have bad breath odor that smells like ammonia and/or feces. i was tested negative for halitosis, negative for sinus or tonsil problems and gi tested?

Not clear: How can you be tested for halitosis? Are you referring to a device which samples sulfur based compounds? If so it can be dependent upon when you are tested. In my experience issues as yours almost always involve foul smelling material that can form in the tonsil tissue that is found not only on the sides of your throat but in the back of your tongue as well. You need an ENT evaluation.

Bad breath: Many things can contribute to bad breath. It usually helps to brush the roof of the mouth and tongue. Better yet is to get a tounge scraper to clean the surface of the tongue, where lots of bacteria tend to accumulate. Patients with gum disease often have oral malodor.