RepairPal Certified shops can diagnose and repair your 1998 Ford Contour. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
This means that an oxygen sensor in bank 1 detected a too much air, not enough fuel in the exhaust.
For more info please go to http://repairpal.com/OBD-II-Code-P0171-and-P0174