hi guys my mondeo failed its mot yesterday on emissions
with CO level to high it was 0.46 and limit is 0.30

before the mot i replaced the cat and lambda sensor
got it serviced etc

so i am unsure what to do now
the car seems to be sluggish since i changed cat etc
also i may be wrong but am certain there is
slight missfire throughout
the driving speed ?

could this be an airflow meter fault ?

can anyone help please ?
thanks kev