US consumer prices rose 0.2% in September mainly driven by energy costs, as inflationary pressures in the economy remained suppressed, the Commerce Department said Wednesday. Energy costs gained 0.8 percent over August, while food prices were unchanged. Stripped of those two volatile components, core inflation was just 0.1 percent in the month. Prices in September were up just 1.2 percent year-on-year; while core prices were 1.7 percent higher than a year ago. The data underscored that economic growth remained tepid in the third quarter, putting no pressure on the Federal Reserve, as it wraps up its October meeting Wednesday, to begin tightening monetary policy.