Haadith collected by Bukhari is divided by sahih (valid)hadith…,vague hadith and unvalid haadith. Unvalid is contradict with Quran so it can not be trusted and we should avoid its practice. It is called a bidah.These hadiths should be rejected.The vague haadith can be trusted although it is not clear but it is not against with the Quran To practice it or not is depend on our own opinion or we can see the opinion of most Mullahs about that.
Some of the haadith which totally contradict the Quranic Verses:
CONTRADICTIONS BETWEEN THE HADITHS AND THE QURAN - Quranic Researh Group - www.quranic.org