>Do you think the hcs would be as high as 290 on idle with a duff cat?<
That is why I would want to check/clean the injector!
If the cat is dead it is because something killed it!
I would also wish to change the lambda sensor on the grounds that it is probabally past its best, most have design lives of arround 50,000 miles (some, astonishingly, particularly on fiats, have design lives of only 30,000, this is from the bosch catalog BTW)
This is ofcourse all assuming that the claims made in the original post regarding valve clearences, ign system etc being up to spec are correct.