P0030 Mazda - Why so fast?

Question

I have replaced few months ago upstream O2 sensor and just yesterday i got this CEL P0030 with P2251 and this means that the O2 sensor is gone again? I use Bosch brand when i replace it but why so fast? Is there something else wrong that causes them go out so fast?

Answer 1

The bracket where the 02 sensor harness clips onto that is on the exhaust what happens is the wire get cut there, You did not lose the 02 sensor, you have a damage wire, see what you can salvage with a repair.