What does max promise grim in chapters 15 and 16 in Freak the Mighty?

In chapters 15 and 16 of "Freak the Mighty," Max promises Grim that he will stay out of trouble and be responsible, especially regarding his friendship with Kevin (Freak). He reassures Grim that he will be careful and not let his emotions or the influence of others lead him astray. This promise reflects Max's growing sense of maturity and his desire to protect those he cares about, including his family.