Mazda 3 2004
 

So. I have a problem with my check engine light.
Was at the mechanic and he said it was the "lamba sonde" (dont know the name in english) or the catalyst.
he replaced the LS and the CE light came back.
Now I've left car again at the mechanic and now he's saying that the car has 2 LS and it might be the other one.

Is this possible ? And what could i do ?