Hi guys long time no see
I have an focus sedan 1.6 ghia edition Zetec -S, and the car failed MOT with some strange values on lambda = 1.4 and CO = 1.2 (all only on >2000rpms), idle is ok.
Previous owner changed Cat about a year ago and engine is 100K miles only on it.
What could be wrong? Thanks

 

Exhaust leak is a possibility.
Do you know what the value of CO2 and HC was?

 

Hello,it was a leak, all sorted out. thanks