Nice one guys, just looked and have an OBD2 installed, i'll see what my mates diagnostics (Toyota main agent) throws up tomorrow, then i'll be back for more info if i get a code!!!
Apart from the light, the car is running perfectly normally, i'm taking it steady accelerating just to be cautious.
I've had a quick look at the CAT and can see 2 sensors, am i correct in thinking that the foremost one actually feeds back and affects fuel mixture whereas the rear sensor monitors CAT function - I guess both could cause the CEL to illuminate?