Hello all, my first post.

My post cat lambda sensor seems fine it, it reads from 0.020 volts to 0.900, my pre cat lambda sensor however never reads above 0.020V, and tends not to change much at all. Even if I remove the sensor I still get a "ghost" reading of about 0.020V?? (This doesnt happen if I remove the rear sensor, it reads 0.000V) I have replaced the sensor and it made no difference at all, and I think I may have replaced a perfectly good part. Is there something else going on with the electrics of the car? It continually throws the engine malfunction light, with a code of P0125 but I have been assured it is a lambda sensor problem and the scan tool readings seem to back this up...

Any help would be much appreciated!