Oxygen Sensor

[Felix.]

The engine light is on (2012 Fiesta) and I have been informed by the garage that it is one of the oxygen sensors.

Looking on eBay, there are ones for sale for about £15 new

Are these items specific to a engine or are they fairly standard parts?

And are the pre & post Catalytic converter sensors the same thing - ie can i just buy two of the same items and replace them both?

[Luke4efc]

Forscan should be able to tell you which sensor is triggering the code.

The o2 sensors are different though, they have different wiring connectors. However, you haven't said what engine you have so can't say what part numbers you need.

A 2012 is a mk7 not a mk6 btw.

[Felix.]

Its a 1.25 zetec 

[Felix.]

Placed this on a OBD scanner which gave the following results.  Taken from a coldish engine:

 

Oxygen sensor 1 Bank 1 Voltage - 0.16V

Oxygen sensor 1 Bank 1 Short term fuel trim - 3.13%

Oxygen sensor 2 Bank 1 Voltage - 0.48V

Oxygen sensor 2 Bank 1 Short term fuel trim - n/a%

 

The "n/a%" never changes as I rev the engine, where as the other values do fluctuate

Is this normal - or does it appear that one of the sensors has stopped working