The federal Environmental Protection Agency yesterday declared Maryland one of 11 states the agency believes to be in violation of the Clean Air Act for failure to set up a required auto emissions inspection program, a finding that could cost the state a portion of its federal antipollution funds.

Maryland officials, however, promptly responded that they can show EPA that the inspection stations are under construction and a program to test auto emissions will be operating by January 1984. "If we don't falter and continue our good-faith efforts, we don't expect any sanctions to be imposed," said George Ferreri, director of the state's Air Management Administration.

The state's long-delayed emissions testing program was supposed to be operating by last January in order to meet a federal EPA deadline. But the program, which will cost consumers $9 for each annual inspection, ran into political troubles in the 1982 election year. Some legislators balked at imposing a new burden on Maryland drivers who do not now have to have their cars inspected and there were signs that the Reagan administration was backing off enforcing the standards.

Gov. Harry Hughes, seeking to avoid a potentially embarrassing election-year showdown with the legislature, delayed the program's start-up date by six months, well past the November l982 election and six months past the federal deadline. His action stopped the move in the General Assembly to repeal the program.

However, the legislature still prohibited any state expenditures for construction of the inspection stations until after its 1983 session, according to Ferreri. That again delayed the start-up date to January 1984, he said.

The inspection program, designed to reduce the emissions of carbon monoxide and hydrocarbons into the air, will operate in Montgomery and Prince George's counties and in the city of Baltimore and its surrounding areas. Fifteen states now have such programs, according to Christian Rice, an EPA spokesman. Both the District and Northern Virginia now inspect for auto emissions, he said.

Yesterday, EPA administrator William Ruckelshaus announced that he would impose sanctions against Maryland and 10 other states if they failed to implement the emissions testing programs the states previously agreed to operate. The states will have until mid-September to show "concrete evidence that they are making good-faith efforts to implement the programs expeditiously," Rice said. If they do, the sanctions will not be imposed.

The possible sanctions include withholding some or all of federal antipollution funds. Maryland receives about $1.5 million a year in such funds, according to Ferreri, and they account for about 40 percent of the state's air-management budget.

The EPA cited 10 other states it believes failed to comply with the auto emission inspection deadlines: Illinois, Indiana, Kentucky, Michigan, Missouri, Nevada, Pennsylvania, Tennessee, Texas and Wisconsin.