If I co-signed on a car a few years ago?

I co-signed a car loan with my now ex a few years ago. The car ended up gettng repoed after we broke up. My ex filed for bankrupcy so he doesn't have to pay the amount owed on the car. Am I liable pay for the amount owed on the car since he filed bankruptcy? I am confused. Please help! The lawyers called and said I have to pay but I m not sure how all the stuff works. Thank you for your time!