Ah! I never new that? I thought if the cops spotted it, you get slapped the huge fine.
I was under the impression that no cat on any car would give flames? But that's what some random exhaust shop told my mate. He got a straight through pipe with a 5" canon on his old banged up Cressida a while back. No cat, no resonators, nothing. Sounded real beefy but shot out massive flames. The guy at this exhaust place said "haha no cat means huge flames!" but he did have a leak in his manifold. Maybe this caused the flames?!
Amazing thing was, even going through defect stations with this thing, the cops never once said anything about it. They always would shine their torch on the canon, but never said anything! Even at idle, it rumbled away and was fairly loud.