Dear All,
My Mini threw CEL this morning. I checked it with ISTA+ and there are two faults:
1. Too lean mixture (002BC0)
2. Oxygen sensor after catalytic convereter, too high internal resistance

I did some testing and faults appear once engine gets warm. First appears the fire st fault, than after longer driving - the second one. I have checked the oxygen sensor after converter with multimeter and it shows 6.6 ohms. Is this correct value? Or should the sensor be replaced? Shall i be looking for other symptoms or perform any further diagnostics? The car has 60k miles on it.

 

Did you ever happen to resolve these issues? I've been getting the same codes in ISTA and tried replacing the rear O2 sensor with an OEM one. Still get the same codes with the addition of P0136.