I had a tibia spiral fracture a yr ago had a nail and 4 screws, non union so larger nail and screws removed but still having pain, what's going on?

Nonunion. An xray is needed to see if the bone healed if not healed that could be causing the pain. If bone is healed pain could be coming from soft tissues or from the metal. Needs evaluation.
Not done yet. There are several possible reasons why you are still having pain. The fracture may not be healed, or there may be a low grade infection. Some times the hardware itself can cause discomfort. You should return to your surgeon and have them evaluate you.