Hi Shaun,

I agree with all the others in that the Cat is faulty plus another problem. If this car had no Cat, then the HC reading would be too high for a pre-cat car. The CO is not high enough to produce this amount of HC therefore there must be an under-lying problem and the fitting of a new Cat may not on its own get it through the MOT. Did the fitting of those ignition parts cure the 'mis-fire'? Afraid its back to basics on this first before any more money is thrown at it.

Regards

Pete M