Failed m.o.t on emissions

Hi all, iam new to this site so sorry for being a bit slow i have a 1998 freelander that has just failed the m.o.t on emissions they are to high readings are 0.6 have had the cat changed for new and a scound one also put on , have cleaned the plugs, air filter, looks ok the workshop were the work is being done have put it onto a tester and they say the lambda is also ok.

looks like they are now going to remove the injector/rail and send it off to be checked/cleaned or something like that on this coming monday but just not sure about this, should they also be looking at temp sensoe/o2 sensor/ more up market cat which they fitted, the m.p.g is not to bad as a run to London just befor test returned 33/35mpg, when warm no smook coming out the rear runs ok, so if you can point/help me in the right way please do and thankyou Monty

after market cat are known to be troublesome.

1.8 k series?

you also need to be careful what coolant you are using as the 1.8 normally uses more water in the combustion chambers than petrol

What is the HC figure? This will give a good indication of how well the engine is burning the fuel. If everything thing is ok then I'd expect to se a reading of between 10 and 70 ppm if so then as already said the cat is suspect! Is the engine light (MIL) on ?

If u post a pic of the emissions report I will point you in the right direction