How many o2 sensors does the 2011 Ford Fiesta have?

The 2011 Ford Fiesta comes witH2 O2 sensors on the vehicle, one of them is located before the catalytic converter and the other one is after it. This is how the vehicle measures the exhaust gasses to make sure that the air to fuELRatio is correct. When there are problems with the O2 sensors in Your car You usually will notice that the engine runs rough and it may wind up running rich or lean depending on what has failed with the sensor. It is also very common that You will get a check engine light at Your dash and when You scan the ECU it will let You know which sensor has detected a fault or failed.