RS Clio 182
iv recently had my emissions light come on but no adverse running, im finally off work so gunna have a look tomorrow and get it plugged in on monday if i cant diagnose myself, can i check the lambda sensor and the cat to see if they are operating correctly and am i right in thinking its the post cat if the light is on but still running ok, my mpg is poor though, could this cause it and also if i do get it plugged in will this tell me which lambda is faulty, anyone have diagnostics in north east, dont mind paying, cheers