Hi, my name is chris.
We have done 3- 4 engine management diagnostic tests on an 1800 petrol ford focus, 2002. The same code keeps re-occuring which is po141. We have renewed both lambda sensors but management light comes back on after only a mile or so. Has anyone any ideas? Always states that heated circuit is faulty,any tests for this?

 

If the sensors are dropped it can knacker them as they are very fragile. Could it be that the new sensor has been damaged? Could be worth changing the pre cat sensor again. I think they also use the coolant temp sensor to measure the temperature switching time. Could be worth changing this sensor too just to rule it out?

 

Thanks very much for advise.
Chris

 

P0141 - O2 Sensor Heater Circuit Bank 1 Sensor 2
Bank 1 sensor 2 is the post cat sensor. You only need to look at the post cat sensor. Pre-cat O2 sensor has got nothing to do with this problem.
Seems the heating is not working (correctly). Check wiring and fuses.