As a followup to T.L.'s thread, it is possible to pass the IM 240 test with aftermarket cats. As I mentioned yesterday in his thread, my Toyota Camry Cats failed so I got some 2.5" off the shelf Euro 4's made by Cateran and it passed this afternoon with no problems. These new cats are physically smaller than my Camry ones. Interestingly another Cobra with a GM donk passed the test this morning according to the test guys. It must be a record!
I am now a very happy chappy
Now to book her in with Bernie for final approval, (I hope).