'03 Impreza Outback,automatic, 2.2L, 182K miles. Recent purchase...maybe 400 miles. Advance Auto computer says something like "emission control not at full efficiency." Young man who tested says try some fuel treatment and light may go off.I had a bottle of Techron on hand so put it in today. Is is likely that his..or Lucas, or Seafoam might actually "fix" the problem ? With 182K I'm pretty skeptical and thinkinh maybe big bucks...cat converter may be toast ? Any thoughts or suggestions would be appreciated !