Gambit

iTrader: (6)

i have a 06 2.5 STI - currently it has the std 2 catted downpipe. This is the later downpipe with the longer 2nd cat pipe.

been on the lookout for later style PPP sport cat (bellmouth & metal cat cover) plus 2nd cat bypass but havent been able to find any

but i have stumbled upon a Decat pipe for the First Cat in the downpipe

i need a cat in place for MOT & cant be arsed swapping in & out every year - so what implications are there for leaving the 2nd cat in.

Is it enough to pass MOT tests?
Is the 2nd cat more restrictive than a sport cat?

will be mapped accordingly.

Infected by sti

iTrader: (6)

The second cat won't really do a lot fella IMHO, the majority of the emissions are cut down by the main cat straight after the turbo, the second is a kind of after cat so to speak, it clears up any light crap that gets through the first, so if your thinking of removing the first one, just remove them all would be my advice as leaving the one in wont be doing much at all, you can fit a complete exhaust from a classic on your car if you use the complete system, not a lot of money second hand on here and will replace both the cats at the same time, just a thought

Gambit

iTrader: (6)

aye was just an idea, ill prob just hold out until i find a ppp downpipe - im just impatient. downpipe/mid pipe is all i need. already got a cat back on it

Geds

iTrader: (4)

I put a Hayward & Scott 3" decat down pipe on, left the second cat in place, a H&S de- resonated centre section with a Blitz nurspec S back box. Sounds great, plenty of breath for 350 and passes the MOT

07 Hawkeye STi

Infected by sti

iTrader: (6)

Your one of the lucky ones then

Rb320 with cobra exhaust and tried retaining the secondary cat and it had no chance of passing the emissions, she then tried a "sports cat" had to get it near enough to melting point lol and it was just making the emissions, in the end she just ( I say she, her bf was the one pissing about lol ) went with total decat for the hassle of scrapping the emissions and now uses a friendly mot garage, I honestly think your the first person I've heard of passing the emissions with the smaller cat left in place, fair play to you!

Geds

iTrader: (4)

I do have a JGM remap with dual maps on racerom. At MOT time I put it through on the lower map which is 320bh. I didn't specifically ask simon to make the "road" map any emissions friendlier. And we don't have such a thing as an MOT friendly garage here in NI.

Gambit

iTrader: (6)

Hmmm interesting Geds!

Gambit

iTrader: (6)

Was eyeing up this but its sold

click me

had never seen one before for the shorter downpipe