romford-boy

I'm looking at changing the downpipe in my standard 2005 STI exhaust system ahead of a remap.

Sadly sports cats (would like it to pass the MOT) are very expensive

How much louder than a sports cat is a decat down pipe? And will I be likely to fail the MOT?

DantheMan2605

I would say, decidedly louder. the afterburner box defo won't help.

No it won't pass mot. But they may be ways it can be made to pass.


Finally broke the Missus to get it mapped then?

romford-boy

Haha, yes she said I can as long as it is no louder....and I don't really want to have to fork out for a Miltek system

Hmmmmm, guess I had better keep my eyes peeled for soemthing like a Prodrive downpipe.

What exhaust system are you running on the new engine?

Sheepy Sean

iTrader: (1)

I had a decat downpipe fitted to my 2.5 and still passed the MOT with the 2nd cat in place (between the down pipe and centre pipe). Assume yours is a 2.0 so might be slightly different but believe the 2nd cat would still be there so you shouldnt have any issues.

As for noise - I couldnt really tell the difference after the decat.

derek sti

Plenty of breakers to get sports cat down pipe for a decent price.
Mine cost £150 for the prodrive one flies through mot with nur spec system and still nice and loud.

Petermaccoll

I will have a prodrive sports cat for sale soon from my 2005 sti(as well as a blitz nur spec r system as im having my exhaust system upgraded, just awaiting a date when they can fit me in i agree with derek sti, sounds amazing too!

bigballs

iTrader: (8)

Can I bump the thread to ask a related question as I am looking for a decat downpipe.

I have a Fujitsubo exhaust which is circa 2.7 meters lon and I believe it replaces the back box and center section cat and joins directly to the down pipe.

I have spotted this for sale, is it the correct size as some of the downpipes I have seen seem much larger?


I have had a look under the car but it is difficult to work out where the downpipe starts and ends as there are heat shields and under trays.

DarrenSTI

iTrader: (3)

Search the ads for a Prodrive Cat, widley regarded as the best one. This WILL pass the MOT, then depends what system you mate it upto really for loudness.
Personally I've run full H&S, even a straight through Race Tube,currently Nur Spec back box, sounds the best yet, but it is loud!.

bigballs

iTrader: (8)

I have fujitsubo system, Im not too worried about the sound as long as its not to ott during normal driving. Im planning to go fully decatted as its a wrx and every little bit helps!

bigballs

iTrader: (8)

Does anyone know if this downpipe is too long for my exhaust? I think that this one replaes downpipe cat and other cat - I only need something half this side?