I need to get my Tiger Avon MOT ,it was registered in 2004 & has a cbr 1000 rr engine.I have been told it needs a cat fitted to pass the mot,i have previous mots which it passed without a cat.So not sure who is right.Can anyone give me some advice on this, thanks.

you need to check what it has on the front of the v5.
Also if it's a Q plate, more likely to sneak through without cat.

Technically, it should really have a cat, due to engine age (i assume its post 1995) and reg date

It really depends on the limits stated on the mot testers system, linked with dvla, if they didnt enter any limits when it was registered, then its visible smoke test