I am actually impressed with myself.
Oh good news, took the car to sheffield subaru services to look at my exhaust as I got told the 2nd cat had gone, the lovely men checked it all and said there's nothing wrong with it and no need to change it. Apparently I have a non genuine subaru cat on it which could have caused my light to come on as it,s not been on for months now.
So now I,m not forking out £350 for a new exhaust system, I think I,m going to have a full service on it at £370, which includes brakes, timing belt, all liquids changed and plugs.
So it will be good as new then :D