P221401 nox sensor cyl bank 2 2014 e350


Could this likely be just a loose electrical connection or more likely the sensor is faulty?
I need to get it up on a hoist sometime and got through the star fault test procedure and see if I get anywhere with that.
Anybody had this fault before?


Can anyone tell me if this car is supposed to have a NOx sensor? Is the NOx sensor just for the diesels or do the petrols have it aswell?
I have been through a few diagnostics and the 02 sensors are all fine. The NOx sensor is an actual nitrogen sensor so thats another sensor?




Can anyone tell me if this car is supposed to have a NOx sensor? Is the NOx sensor just for the diesels or do the petrols have it aswell?
I have been through a few diagnostics and the 02 sensors are all fine. The NOx sensor is an actual nitrogen sensor so thats another sensor?


Im not 100% sure but the car has 4 oxygen sensors. One sensor before the catalytic converter and one after on each exhaust line. The ones before the converters are the ones that are used for the engine control. The sensors after the converters tell how well the converter works as it should change the amount of oxygen after the converters. Maybe the oxygen sensors after converters are called NOX sensors too???
My question is can you clean them? Iv heard you can clean o2 sensors in the past with something like lemon juice?




