In Chapter 1, Nick Carraway describes himself as honest and objective because he has established the reputation of being a non-judgmental listener. He gives the example of hearing the woes of his college cohorts and not only being discreet about them but also not judging the storyteller for whatever he might have done. This attribute of objectivity, according to Nick, allows him to offer his honest opinion and to narrate the novel without bias.
Of the major characters in the novel, Nick is honest. However, he does assist Daisy in deceiving her husband (regarding Gatsby). Nick is most guilty of dishonesty by withholding the truth. He does not tell his cousin that her husband has a mistress and that he has met her. He does not correct Myrtle's sister Catherine when she spreads rumors about Daisy, and most importantly, he tells no one that Daisy was driving when Myrtle was killed.
he doesnt mean honest as in not telling lies he means that he is honorable in his principles, intentions and actions, he finds thathe has honest commodities