Why engine light is on?

Do I knee a new brack caliper and brack line.

Hello, your check engine light will not be on because of any issue related to the brakes. This will need to be inspected independently of your brake concern. As far as a brake or caliper issue, this requires first hand inspection. Since this is a major safety item, I can't stress enough that you get professional help soon, for the safety of you and other motorists.