New Jersey’s attorneys argued that federal and Metropolitan Transportation Authority officials “did it backwards” by approving an environmental assessment of New York’s congestion pricing plan before the MTA approved the final toll rates last week to charge drivers $15 to enter Manhattan south of 60th Street. Randy Mastro, attorney for the state, argued in federal court in Newark Wednesday that the MTA should have conducted a more comprehensive Environmental Impact Statement study. That study is required by environmental law, he said. It also is warranted by the MTA’s own findings that congest…