Focus Fault Codes P0036 & P0136

[SFO]

Hi, just had the engine light come on and the diagnostic has come up with these 2 codes. I think they both apply to each other as a quick Google search said it was a temperature sensor I think in the exhaust. I had hoped it was just an error and tried to reset the codes both on the diagnostic and by disconnecting the battery for a while but neither have worked. Anybody have an experience of this or any ideas on a cure?

[iantt]

hego sensor downstream of cat at fault, either wiring or sensor faulty, needs testing with a multimeter.

[SFO]

Thanks for the reply. Any idea how hard a job it is to replace the sensor??

[SFO]

Decided to try and sort this myself. I've found the lambda sensor at euro car parts. Trouble is, where is the sensor? Had a look under the car and can't find the sensor. Is the sensor toward the front of the car?

[Simonpcroot]

Ive got same issue changed the post cat sencer easy to do 

but keep getting the fault code back after i rest it

Its the blue wire fixed to the exust just bellow the cat 

it plugs in back of the engine under the big black breather tube just split it at the conections and remove it you can just see the plug its tight. But doable