A bill to amend the Clean Air Act, as amended.

[AI summary unavailable — showing source text] Amends the Clean Air Act to postpone until model year 1979 motor vehicle emission standards which require a 90 percent reduction in emissions of carbon monoxide and hydrocarbons from light-duty vehicles. Extends interim standards for such pollutants through model year 1978. Revises motor vehicle emission standards for nitrogen oxides to extend interim standards for an additional year until model year 1978. Requires vehicles manufactured in model year 1979 and thereafter to meet a more restrictive standard of 1.0 grams per vehicle mile. Authorizes the appropriation of $300,000,000 for each of fiscal years 1978, 1979, and 1980 to carry out the Clean Air Act.…