As far from JBS as possible !
Any garage should be able to just cut out the CAT and wield in a new piece of pipe or go to a custom exhaust place like Powerflow etc.
06 Audi 2.0 PD140 Sport TDI Quattro S-LINE.
Old engine 330 bhp @ flywheel 263 bhp @ wheel 490 lb torque.
Audidriver write up HERE
Now stripped and playing with an uprated Cryo treated engine fitted with bigger turbo,water/methanol,uprated injectors etc etc.Wanting 400 bhp and 500 lb torque.
Other car 500+ bhp MK4 Golf R32 turbo