Krebs is reacting to the less than warm welcome he received after returning to his hometown after serving in the Army during World War I.
Most of his fellow soldiers had returned home long before he was able to do so. The town had already heard all the horror stories and had grown weary of the tales of pain and suffering. Krebs soon learns to not tell any of his own experiences to anyone. His inability to express himself causes what we now know as depression.
The line that you are inquiring about, wanting to "live without consequences" comes when Krebs is contemplating becoming involved with a woman. He decides that he "did not want to get into the intrigue and politics." The whole idea of having to form another human relationship is too painful. The horrors of war combined with the callousness he percieves in his hometown causes Krebs to lose hope in life.
A Hemingway code hero, Krebs wants to "live alone without consequences" because he has felt the "nausea in regard to experience that is the result of untruth or exaggeration." In short, he does not want to live without truth.
When Howard Krebs returns home from the war, he discovers that people do not want to hear the truth about what has occurred; instead, they desire stories of heroism and exaggerated incidents. Because they are not thrilled by the reality, Krebs finds himself telling people lies, and as a result Krebs begins to feel disinterested in everything and ashamed of himself.
Krebs also decides that he does not want to have a girlfriend because in a relationship there are usually lies, as well.
Like the code hero that he is, Krebs decides that he must leave home and act alone in order to be able to face life honestly and with courage. His final scene with his mother convinces Krebs he can no longer stay with his parents when he has to act as though he is still a boy and promise them that he will try to be good. Only by leaving can he be free-willed and true to himself.