The MOT bit is a gamble - my understanding is that is does not legally need to be there BUT your car will need to achieve the appropriate readings on emmisions for cat'd cars - not immpossible if your car is in good order tune wise.I would assume some gain could be had as less restriction but as a sports cat would assume quite good as passing exhaust gasses. My intention is to remove the standard cat when I fit a JT 3" front pipe and run de-cat'd.
Whilst on this subject Saab dealer told me Friday that there is no gasket between the turbo and the front pipe - Is this correct?
there is no gasket between the turbo and downpipe on my 96 900. other models im not sure about. from my understanding 1996 and up saabs have 2 o2 sensors for the cat...one before and one after. the one after is goin to give you problems if you try to put a straight pipe where your cat is. the best thing to do is get a 3 inch cat. around $140 from summit.