California is expected to follow through on its threat to sue the U.S. EPA this week for not yet deciding whether to give the state the waiver it needs to implement its 2002 law limiting greenhouse-gas emissions from cars. The state’s law requires a nearly 30 percent reduction in greenhouse-gas emissions by 2016, which experts say can only realistically be achieved by upping vehicle fuel-economy — something the automakers argue can only be set by the feds. California applied for the waiver in December 2005; the EPA has promised to make a decision on it by the end of the year, but state officials are skeptical. State attorney general Jerry Brown said of the EPA, “they require continuous, persistent pressure” — just like a wound. The suit will likely be filed on Wednesday in a Washington, D.C., federal court.