so i have a hawk sti with a full 3" decat system.

3" downpipe of unknown brand
3" center section by scoobyworld (afterburner) non-resonated
3" afterburner vortex backbox

my usual guy i use for mot's cant do them anymore so i think its easier if i get him to fit a cat just for the mot, exactly which one would i need?

cheers

 

Just get a sports cat bud 200 cell or a Prodrive one think there 200 cell aswell. Got one on my Impreza that I bought off here works well.

 

are they available in 3 inch fitment?

 

Prodrive are 2.5....I think scoobyworld do one in 3 inch

 

so am i looking for a sports cat in the downpipe or in the center section?

 

You want it closer to the turbo than the backbox or wont heat up and chances it can fail when cold

 

ok so ideally im looking for a downpipe with a sports cat then in a 3" fitment

 

something like this might do.

https://www.ebay.co.uk/i/15119964783...3D151199647837

or try find something 2nd hand and cheaper

 

is it me or does that look like it tails off to 2.5" fitment

 

As Smurf said, it wants to be as close to the turbo as possible. Cat in centre pipe won't work. I have a friend who has a Litchfield Forester STI and it has a sports cat in the centre pipe and fails MOT emissions every year without fail.

Cobra make a full 3" downpipe with sports cat.

 

apologies your correct as standard card have 2.5" here a full 3" one which is unbranded https://www.ebay.co.uk/itm/230788197510 a cobra one will cost you double https://www.ebay.co.uk/itm/332390893715

 

Is it to be fitted all the time or just for MOT`s ?

Reason i ask is it take ALOT of heat to get my sportscat close to passing a CAT emmissions test, i mean, up and down the bypass twice at 70 , ingo MOT station and do emmssions test straight away and then it still needs idle revving to get back to correct heat.

if its just for mot id stick a normal cat in it to be safe

 

Save some cash to prob, if only for the test

Had a Saab Hot Aero with Sports Cat which needed to be roasted to pass

 

To be fair i need to give mine a blast to pass, but always does, thought thats because mine is just a summer car. Thats 200cell, you can get 100 cell that should pass alot easier. Also mine is heat wrapped. Be worth wrapping your exhaust manifold aswell if you go down this route.

 

Think you'll find that's the other way around.

200 cel is more MOT compliant and easier to pass than 100 cel which is less restrictive and lets more harmful particles through.

I had a 200 cel cobra on my car and passed MOT fine every year without having do drive it like I stole it beforehand.

 

thanks for the advice guys, i may try and find another place that will do it for me as i cant be bothered with the hassle. theres loads of tricked up cars around here so chances are most are running a de-cat