I hope so!What did you do with the wiring from the cat temp sensor when you removed it? If it was that light that flashed up maybe the wiring momentarily shorted somewhere causing the light to come on?
I have a power FC and i got told the engine management light would flash fast or slow if DET?What ECU do you have? Is it possible it's some other warning like the way the PFC tells you about DET?
I'd suggest the same thing about the hot dog sensor though; mine just comes on when I've been out in the snow, which is obviously and electrical short that only happens occasionally.