I have a goodman furnace but I seem to have misplaced the tag that was inside the furnace letting me know the model number of the furnace. I treid calling the company and they have no way of finding it and I don't believe the previous owner registered the furnace when it was installed. Is there any way to find out what that model number is since the tag is lost?

Slim... very, very slim... You've have to find a guy that's serviced and installed 100's of that model, and find him to identify it from memory. And even then there are usually changes in the system mid run for a given model where a Serial number would be needed to identify the correct parts.

Why was the tag even removed..