FOCUS RS OXY SENSORS MIL LIGHT
 

HIYA GUYS THE ENGINE LIGHT CAME ON ON MY FOCUS PLUGGED A BLUEFIN ONIT AND FAULT CODE P0135 CAME UP WHICH IS OXY SENSOR 1 ANYBODY NO WHICH SENSOR IS THE NUMBER 1 ??? AS THERES 1 IN THE CAT AND ANOTHER IN THE FLEXI PIPE APPRECIATE ANY HELP AND AT £100 EACH IDEARLY YOU WANNA GET IT RIGHT 1ST TIME ?? :?

I'm pretty sure thats the first one i think its green plug, i'd the 2nd one go on me - the blue plug.
Sometimes cleaning them with carb cleaner fixes it.

Jonny