Hi Don't no if you had the problem resolved, I only just log on for the year. I had a similar problem with a 2000(W Reg ) The cutomer said the car had problems with the Emission the previous year. I carried out a leak detection test and it turned out the Cylinder Head gasket had a leak resulting in the O2 sensor not registering correct reading and ECU was compensating fuel.with the amount of fuel the New CAT could be rendered useless very quickley