17b Ritva s.v. aderabah. The Gemara implies olah isn't mechaper. But olah is mechaper for asin and lav hanitak l'asei! See Rashi Vayikra 1:4, Rambant here, Baalei Hatosfos there, Yoma 36a and Gilyonei Hashas (by R'Yosef Engel) there, Rabi Akiva's opinion in Toras Kohanim 1 Dibura D'Nadav parshasa 3:8, Tosefta Menachos 10:12, Rambam Maasei Hakorbanos 3:14 (thanks to Torah Shleima 105). The Ritva answers even though olah provides kapara for asei and lav hanitak l'asei, the olah's purpose is not to provide kapara for these things; the pasuk only promises that you will get kaparah for the listed things.
My question is, on Yom Kippur we say in the viduy "v'al chataim she'anu chayavim aleihem olah." But according to the Ritva, we're never chayav to bring an olah? (I don't have an answer.)