when i got the car i was told the cat looked new, the thing with the spark plugs has been sorted, ended up being that the nos leaned out in two cylinders.
i didnt have an O2 sensor for awhile, in the last service it was discovered that it wasnt working, but i dont know how long before that it had not been working for.
there is no point in me getting a high flow cat, there are no benefirs, i have already been told that by John Keen, if it was turbo then yes it would be worthwhile, but cause im all the way naturally aspirated, there is just no point in me spending the money on something that is not going to benefit.!