stigaz

i've asked this here before and asked subaru specialist garages and exhaust suppliers all with differant answers.
now i have the exhaust waiting to be fitted will it be safe without a remap or should i keep the centre cat on untill the remap?

gary

fishfire

Yes should be fine without a remap. I know of a classic sti which has been fairly well modified: full decat, filter, increased boost, fuel pump etc and has neverhad a remap (standard ecu) and made a tasty 320bhp, fueling was all ok and knock was minimal.

Obviously to make the most of any modifications and get maximum gains, a remap would be in order.

Depending on the year of your car, if you fully decat, your ecu might throw up a CEL due to lack of catalytic converters, but this can be removed once you do get a remap.

haroldhettaturbo

iTrader: (2)

Asked the same question to Kev @ the clinic. He advised that classic ecus were fine with full decats.

gti00eater

how many cats is there i was looking to remove mine but it thought there was only 1 ??

Dee NI

There is one just after the turbo and one in the middle section or there abouts. To save on MoT trouble you're best leaving the first cat in or getting a sports cat. Then removing the last one.


Damien

stigaz

yes one in the downpipe and one in the centre section on classics,think am going to go ahead and go full decat plan to put the centre section cat back on come mot time or some garages ,theres one near me,that puts a custom double catted centre on for mot's for £40 ,but i'v heard of people passing with the centre one fitted.
i'am going to be wary of putting the foot down though at track days or 1/4 mile,was thinking of getting a knock sensor but this is money i could put towards the remap

gti00eater

would you get any gains from only removeing the center one then? i was realy only looking a bit more noise/flames as mine is a bit to quiet

stigaz

i,m sure there would be some gains as the system would be less restrictive,i think i heard the downpipe cat is the most restrictive of the two though

hux309

I was led to believe that classic only have the one cat in the downpipe, the box in the centre section is just a silencer.

Either way mine is fully decatted and running sweet as making 0.8bar on standard ecu.

Pops on occasions too.

fishfire

Definatly two cats! One in centre section and one in the downpipe. Full de-cat is the way ahead and definatly worth the hassle of refitting one of the cats at MOT time. when I decatted I instantly noticed a vast improvement in turbo spool up, and made some more power in conjunction with other mods and a re-map.
Centre de-cat is the easier one of the two to replace at MOT time lol!

renno rannes

I think the UK car has a CAT in the centre and JDM has a resenator in the centre. Both have them in the downpipe.

I wouldent have a decat downpipe without mapping. I also thought if any ECU could handle / retard better with a DECAT it would be the newage Denso one rather then the GC8.

gti00eater

my car is a jdm sti ra only reason i realy want to remove it is the car is way to quiet what is a resendator? if i only remove one will it make it louder i dont want it to loud just want it to sound like a scooby lol

fbladerrv900

I ran my scoob 97 uk with full de-cat with no problems, but after mapping WOW what a diference

gti00eater

ok ive been bullied into getting a full decat lol can anyone recomend the best one to buy or where the best place to buy plz cheers

hux309

TSL MOTORSPORT | Subaru Saab Mitsubishi | parts | repair | servicing | performance tuning | UK

Im running the group a decat, centre pipe and the group n backbox.

Decat makes a gorgeous whistling sound, spools up much better.

What renno said makes sence, my car is a jdm so has a cat in the downpipe and the resonator in the centre pipe, the resonator is just another silencer really, best to lose the thing and go full decat.

Im not sure if you will need one lambda bung or two, speak to john at tsl, he's great at looking after people.