Just had the emmisions test done on my 348 this morning. It passed with a comfortable margin. So anyone thinking about getting them in the UK should'nt need to worry. For reference, a 348 with 1 blown cat will also pass. Found this out when I first got the car. Only negative things about the Hyperflow are that it does'nt sound as good or as loud as a decatt (both with a tubi). There is also significantly more heat in the engine bay, than a decatt, although less than standard cats However, I have'nt noticed any difference in throttle response compared to decatt and the Hyperflows are definetly 100 time better than the stock 348 items which in my opinion are crap. Also, my insurance company AON don't have a problem about the install of the Hyper-flows. Conclusion: If you can legally decatt your car, do it and it sounds great with a Tubi. If you have to keep cats on, chuck out the old 348 ones and get some hyper-flows.
For reference, I just MOT'd my 348 with 100 cel X-Ost sport cats and a Capristo Twin Sound and no problems here either.
