from 19th edition emissions book......
max is
0.5% Co normal idol ,
0.3% fast idol ,
200 ppm hydrocarbons ,
Lambda range 0.97 to 1.03
OIL at 80 degrees plus ,which is important
if the car is not up to temp ,it will overfuel badly
if the coolant temperature sensor is duff (common on 4 bangers) it will overfuel (so check live data )
I put cataclean in 1/4 of a tank of petrol, with spirited drive,or later gear changes to rev move,get the cat warm ,then put fresh petrol in before test ,
lambda may be duff or the temp sensor ,car should not go open loop once it is in closed loop
getting the cat really hot prior to mot would probably have seen a pass , your not far off
I'd check live data again if possible, temp sensor and lambdas ,possibly replace them, cataclean ,check and gap plugs, check breathers are clear,throttle body is clean, and get the car warm ,cats hot (Mexican tune up) before taking for re-test at a set appointment , i say this because if the car sits waiting for an hour before test,it will go cold .