Bishops cannot act and teach against the -> POPE, but only with him. In contrast, the Pope can make decisions in clearly defined cases even without the approval of the bishops. [883-885, 880-890]
Of course the -> POPE in all his decisions is bound by the Church’s faith. There is something like a general sense of the faith in the Church, a fundamental conviction in matters of faith that is brought about by the Holy Spirit and present throughout the Church, the Church’s ” common sense”, so to speak, wihich recognizes “what has always and everywhere been believed by all” (Vincent of Lerins).