; and (C) consists solely of carbon, hydrogen, oxygen, and sulfur, excepting any impurities present at trace levels that are gaseous upon combustion. ; and (3) in subparagraph (A) of paragraph (4) (as designated by subsection (b)(1)(A)), in the first sentence, by striking or (3) . 8. Clean octane standard Section 211 of the Clean Air Act ( 42 U.S.C. 7545 ) is amended— (1) in subsection (d)— (A) in paragraph (1), by striking or (o) each place it appears and inserting (o), or (w) ; and (B) in paragraph (2), by striking and (o) each place it appears and inserting (o), and (w)