Help !!
Hi, new to this so be gentle !! Just bought a SportKa that has the engine light showing - I plugged in the reader and it comes up with P0138 error. I know relates to the (O2 sensor circuit high voltage Bank 1, sponsor 2 - is that otherwise known as lambda sensor ?). I know the previous owner changed it for a new one recently but the fault has re-appeared. Could he have changed the wrong one ?
I have read on other forums that if you don't use original ford parts the voltage varies ?? Also that wires could be hitting he manifold ??
Any suggestions to fix this - the car seems to be running fine apart from this light being on ??
Appreciate any suggestions.
Cheers
Rob

 

The code is for the O2 (Lambda or Oxygen) sensor AFTER the cat.
Did the previous owner change this one or the Front sensor?
Did he use an original sensor?

 

I think he got it from GSF so guessing it wasn't original - I will call him tomorrow to confirm this and the location of the sensor. Thanks

 

Hi,
Just got text back ... Part bought from GSF and was for AFTER the CAT. Do you think it could be because it isn't a genuine FORD part ?

 

P0138 says the signal from the rear oxygen sensor is too high.
That is either a wiring (short circuit) problem or a defective Oxygen sensor.

Can you read live data? What's the voltage displayed for Oxygen Sensor 2?

 

No idea how to read live data ??

 

Check wiring for damage or corroded plugs etc, fit a genuine sensor and see what happens. I know the st170's tend to throw a wobbly unless you use a genuine or a good aftermarket sensor like Bosch for example.

 

Thanks all 😊