Reference: http://mufti.af.org.sa/node/2163
Question: Is it correct that the one who does not pray the congregational prayer because the imaam is an innovator – is himself an innovator, bearing in mind the imaam’s bid’ah is not one of disbelief?
Response: The congregation[al prayer] is obligatory, so it is befitting to have a suitable imaam [to lead the Muslims in prayer]. [in the case of this question then], if the bid’ah of the imaam is not one of disbelief, and you fear if you were to pray behind him there would be disruption amongst the congregation, or if you were unable to pray with another congregation, then [you should] pray with him and advise him, and strive in giving him advice, [and] it is hoped that Allaah will guide him.
