Toyota faces a US investigation into complaints of steering problems in the Corolla, the world's best-selling car, in a fresh setback to the auto giant's efforts to restore trust in its brand. The Japanese maker, already pulling more than eight million cars worldwide over defects linked to more than 30 deaths, said Wednesday it was looking into the issue and would recall the Corolla if it found a dangerous flaw. Another recall would deal a heavy blow to efforts by the world's biggest automaker to bounce back from a string of safety issues and criticism that it was slow to...