Hi Max, all 4 Cats had detached/twisted/ broken up, the exhaust system it self was poorly built with some parts of the pipes reduced in diameter, the fixings where broken and the welds onto the silencers had been repaired badly and whilst could be repaired it made more sense to bin the exhaust and have new one made. Now running 1 Cat per side and increased bore to 2 1/4.
Have also replaced the manifold as it was cracked and had a few small holes however, the exhaust outlet on the headers was small than the manifold outlets and thus was leaking. I would also add that again the manifold was poorly made with different length pipes and bends that reduced the diameter of the pipe.
With these changes the car is now showing 270 bhp with 340 torque, next up is to increase the fuel system.