Screenshots of the conversation suggest 27-year-old Mr Findlay had been talking with a 15-year-old.
Now, he has stood down from the candidacy bid and his biography has been pulled from the People's Choice website.
People's Choice campaign manager Sara Epperson confirmed Mr Findlay had withdrawn from the race following a leak from "a personal conversation on a social media application".
"We hold high expectations for our candidates and for the future of the city," she said.
"We do not excuse or condone his actions in any way, and that is why we have accepted his resignation."
A statement from Mr Findlay said: "I regret my actions and I agree my actions were wrong. I have withdrawn as a community board candidate and resigned my membership of The People's Choice Inc. I have no further comment to make."
He's also today resigned as a board member of Q-topia, a social support group for gay, lesbian, bisexual, transgender and intersex youth aged 14-25 in Canterbury.
The group accepted the resignation after the online conversation with someone who identified themselves as a 15-year-old girl.
"We understand that at no time did any interaction progress beyond the online environment," Q-topia said in a statement.
"As a board, we have every confidence that Paul's time on the Q-topia board was undertaken with the utmost integrity, and that he maintained the highest standards that are expected of all board members while undertaking Q-topia duties.
"We respect Paul's decision to remove himself from the board, and believe that this decision has been undertaken to ensure that the Q-topia standards are not affected in any way."
American politician Weiner quit Congress in 2011 after using Twitter to send a link to a sexually suggestive picture to a 21-year-old woman.
Earlier this year while running in the New York City mayoral election, he admitted being involved in more sexting, but refused to bow out of the race, finishing fifth.
