which cat to remove
 

i was going to remove the second decat on my classic but on scooby clinic they keep it and remove the cat in the down pipe ???

i,m a bit confused,i want to remove one of them ,but keep one for the mot .

any help

the downpipe cat removed would require a remap and not pass emissions. 2nd cat would not require remap and pass .

I thought the classic impreza only had 1 cat in the downpipe and that the box on the centre pipe was just a silencer??
And you don't 'need' a remap if you fit a decat downpipe. Just have the boost and air/fuel ratio checked. :thumb: Most common problem you will get is over-boost if any.

uk classics had one cat in the downpipe and one in the centre section if the exhaust was completely standard.

Whats in the centre section of a V3 JDM STi?

think thats just a resonator and silencer - Ive got a v5 sti and its the resonator on it.

Cheers. It'll be up in the air next week so i'll have a proper gander at it then. :thumb:

:brickwall doh, my apologes. did not realise we were on about a classic, should of read properly. 2.5 engines dont like decats though without a remap

It looks like its a cat but its a resonator box.

My new sti5 has a stock exhaust and ill be replacing the centre section with a 2.5 inch bore pipe with a bubble resonator to keep the volume sensible.

My 3 inch bore Hks days are over:freak3:

thanks guys for the advice :thumb: