Yaris verso Lambda sensor

[amazighman]

Hi all.

The wife's  Yaris verso 1.3 2003 failed its mot today , Exhaust Lambda reading after 2nd fast idle outside specified limits .

Does this mean it  needs a new O2 sensor?

I dont know about pre cat one as I cant see it anywhere 

the problem is this sensor wiring goes somewhere  inside the car under the drivers side. ,there is a grommet outside  where wires go inside the car but thats about it.

does anybody know where exactly the  wire goes  or how to get to it?

Or this has to but cut and new sensors wiring  joined onto existing  wires?

thanks