Flyboy-F33

Sorry if this has been done to death, but I've just bought a 98 STI4 (300BHP) with a blitz induction kit and Magnex (dont laugh) back section. Someone said 'get a de-catted down pipe'. My questin is, Will it make much difference? Will it pass an MOT? and Where do I get one? (In Surrey/Hampshire area). I know...that was 3 questions

Flyboy-F33

Come on then....any answers greatfully received.

scoobysnacks

Before I start, a Magnex back box is a good piece of kit - well made with a nice sound and great value (and I've got one) so only a fool would laugh. Anyway, back to your questions: A decat down pipe is a great mod to make as it increases power (maybe 10-15 bhp or so - check the dyno section) and reduces spool up time so the turbo come in about 500 rpm earlier and engine response is much better (more sound as well). Unfortunately, you do not have a centre cat in your car so it will fail an MOT unless you swap back the downpipe, which is not an easy job, or put in a centre cat for the test (and you still may fail unless it's a special one such as those offered by Power Engineering). Finally, where do you get one? - loads of places like Scoobysport, Power Engineering, Graham Goode, Scoobymania etc. sell them and have their own verisons as well as other makes like Magnex (as good as any). Hope this all helps.

S55 HOT

I've got an STi 4 with a Scoobysport downpipe and a Magnex backbox it failed it's MOT

I couldn't be arsed with swapping centre section every year so I got a PE catted centre which works well - passed the MOT and feels better than the standard one - did cost £400 though