The 2006 Ford Escape oxygen sensor is situated in the exhauSTStream. The flash fittings should be supplanted each 100，000 miles except if it's a copper one. A cooper flash fitting should be supplanted each 30，000 miles. Your air channel should be supplanted each 15，000 to 30，000 miles. The coolant should be supplanted each 60，000 miles. You will go over many issues with a motor. A gasket might be free and that should be straightened out. A flash fitting might pop off,causing motor issues. A difficult issue is the motor overheating. This might prompt flames and the vehicle detonating. There could be over the top oil use,requiring the oil to be changed sooner than anticipated. You can have oil breaks and those should be fixed straightaway.