Possible causes – Faulty Oxygen sensor– Ignition problem– Fuel injection problem– Engine mechanical condition Tech description There is a factory service bulletin for the following Buick models: 2000-2008 Buick Century2000-2008 Buick LeSabre2000-2008 Buick Park Avenue2000-2008 Buick Regal2002-2008 Buick Rendezvous2000-2008 Buick Factory Service Bulletin OBDII Code P1174 Symptoms – Engine Light ON (or Service Engine Soon…