A strong sense of honor can lead characters to both honorable and dishonorable actions, depending on the individual and the context.
What a strong sense of dishonor does
In the case of Achilles, though he withdraws from the war due to personal pride, his initial motivation to fight is driven by a sense of honor to avenge the death of his friend Patroclus and to fulfill his destiny as a great warrior.
However, for Agamemnon, his thirst for glory and power leads him to make dishonorable decisions, such as sacrificing Iphigenia and manipulating Achilles. He prioritizes his ambitions over the well-being of the Greek army.