If my co-signor filed Chapter 7, do I still owe on the loan as the primary lender

I think you probably meant to say "primary borrower," didn't you?

If I understand your question correctly, the answer is "Yes, you still owe on the loan as the primary borrower." The fact that someone who co-signed the loan with you has gone through bankruptcy may affect or even extinguish HIS obligation. It doesn't relieve you of yours.