I file chapter 13 over a year ago and one finance company never came to pickup the 4 wheeler. Can I sell this or will I get in trouble?

This is a question for the lawyer that completed your chapter 13 paperwork. Until you find out for sure you should not do anything with the 4 wheeler. If you had agreed to surrender it to a creditor, then it belongs to them, even though they haven't come to get it yet. They will eventually. If it was not to be surrendered, you should still talk to your lawyer, because the sudden influx of cash might mess up your chapter 13 payments.