Possible causes – Faulty front heated oxygen sensor– Ignition misfiring– Faulty fuel injectors– Exhaust gas leaks– Incorrect fuel pressure – Faulty Mass Air Flow (MAF) sensor 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…