Why do i have bad breath after a tooth was pulled?

I am guessing, but if you have a large operation such as a tooth extraction, then the body allocates more of its resources into healing. It is possible that this healing process is generating by-products which have an odour which you are smelling as bad breath.

Also, although dentists try to keep wounds sterile, the mouth is very rich in bacteria so the wound could also be getting a slight infection. Bacteria often cause bad breath and also you may be seeping small amounts of puss as it fights it (yum!)

Try using a little bit of alcohol based mouthwash if your wound is healed up enough. It will burn but it will kill alot of the bad breath-causing bacteria. Also make sure you are brushing your tongue in your daily dental routine and it can harbour like 80% or something of bacteria in your mouth.