No it says if we say we HAVE no sin, we are liars. That would be sin nature. If we say that we have no sin nature, we are liars. Sin is not something that we can possess; it is something we do by obeying the wrong nature.
It says, 'if we say that we HAVE NOT SINNED we make God a liar' (1.10). Anyone who claims he has not sinned makes God a liar