Consumer Prices Up Modestly; Housing Dips WASHINGTON - Consumer prices rose by a modest 0.2 percent in September as a decline in prices for new cars and airline fares helped to temper a rise in costs for medical care, gasoline and fuel oil.    The rise in the Consumer Prices Index, the government's most closely watched inflation barometer, came after prices edged up by 0.1 percent in August, the Labor Department reported Tuesday...