mot station couldn't get emissions reading , anyone know why ?

[Kyle_]

so i took my 2002 2.1L petrol  jaguar x type to the mot station it passed everything apart from the emissions and they said they couldn't get a emissions reading and wanted to put it on the machine to read the engine code since the engine management light is on too but they haven't been able to get me in for almost a month so just want to figure it out myself but before i got a mobile diagnostics guy out to read it i wanted to see if anyone on here can help me try and find out what could cause the engine light to go on and make it so the mot stations emissions tester couldn't get a reading the guy said it could be from a little censor to a catalytic converter. 

- Kyle

[Kyle_]

it inst nonsense im in trade / in the "game" with them so i get to walk around the car so they cant pull that stuff on me i think its MAF sensor anyway at this point because its not getting a reading so it could be caused by too much air going through the system since it doesn't know when is enough or something along them lines just putting too much air to fuel through plus the car feels lumpy or jerks when accelerating so im 90% sure its MAF sensor will put the engine back together once it stops raining for once and will start the car and unplug the MAF sensor  that will give me a little bit more to go off of.

[Kyle_]

also i know the car has little to no emissions because when you start the car and cover the exhaust for like 10 or more seconds you take your arm away and its black the only thing black on my hand was a ring where my hand touched the dirty exhaust.