Every Ford Taurus I have ever owned, ( I've owned three unfortunately) have emission system failure. It is extremely costly. Although you can drive the car until its last legs, it will continue to deteriorate without any hopes of getting it fixed. Every diagnostics is different went attempting to repair it. Sensors, intake valves, exhaust. You name it. The car hesitates and will not go. Not even Ford is able to completely fix this defect and when I Google it nobody else does. If you buy one it might be great for about a year, sell it fast!