Carter Asks Delay on Auto Fumes
EPA Admr Douglas M Costle tells HR subcom that Pres Carter backs comprehensive amendments to Clean Air Act; reveals Carter Adm urges delay in enforcing auto emission standards but generally calls for tough regulation of polluters, including econ penalties on those who fail to comply with clean air laws; environmentalists and some members of Cong, including Sen Edmund S Muskie, disappointed with willingness to put off compliance with emission standards; Sen Gary Hart says he will fight for more rapid crackdown on emissions; GM Corp pres Thomas Murphy calls Adm's emission standards 'unnecessarily drastic'; calls Costle's testimony 'perplexing' (M)