Apologies if the answers here are blindingly obvious -- I've had a sniff around the archives but not sure I've found what I'm looking for.

I've a MY00 UK Turbo which has 2 cats if my memory doesn't fail me (1 in the downpipe and the other in the centre section..?) If I replace the centre section and ditch the second cat, will the car still pass an emissions test..? (apart from a H&S back box the engine is standard.)

Why am I contemplating doing this..? If the car will run happy (read 'emissions') with a single cat then I'd like to remove any unnecessary blockages to improve the flow of gasses a little bit. I think I also read somewhere that replacement centre sections can also improve the characteristic flat-4 burble that the Impreza has(?) I opted for a standard H&S back box a couple of weeks back and although I love the sound, in hindsight I probably could have asked them to make things a tad louder (but without going overboard.)

Thanks for your time.

Jonts.

 

Ya right mate.....MY00 have 2 cats (one in the downpipe and the other in the centre pipe) if you decat the centre pipe you will pass an MOT - no worries (in my situation my emissions actually went down after removing the centre cat!.

 

Thanks Darms.

Since I posted this morning I've also spotted the Magnex rear de-cat pipe on Scoobyparts, which although is marked not for road use is "perfectly legal if the front cat is retained." This backs up what you're saying.

I'll ask Ian at H&S what they throw their centre sections out for. I'd rather not mix H&S and Magnex components together if I can help it.

Cheers,

Jonts.

 

I've done this on my 04 STi, cant comment on the emissions but taking out the centre cat and centre section does do wonders for the flat-4 burble.

Even get some pops and bangs every now and again....

 

Someone please pass me a man-size box of Kleenex!

Jonts.

 

My MY96 used to get through the emissions on just the centre pipe cat. The downpipe cat is the one that seemed to be most restrictive to me...

(I also have a decat downpipe for sale... )