danno_el_mano

New to all this so bear with me...

Got a Jap MY94 WRX wagon with a blowing exhaust. Kwikfit won't touch it but looked at it and said the 'cat is cracked'.

So I'm guessing I need a new downpipe and cat. Correct?

I want minimal fuss and bother - car is totally standard - and keep costs to a minimum. Any point going for a de-cat or is this going to raise MOT and re-map issues? £175ish seems to be going rate for aftermarket downpipes, if I'm looking at the right thing. Was quoted £450 for a 'free-flow cat' downpipe and £400ish for OE.

One thing that was suggested to me was that with everyone rushing to fit de-cat systems there must be tons of OE systems going into skips. If that's the case and it would fit a Jap car (I have no idea about the various compatibility issues here ... like I say, I'm a newbie) I'll gladly take such a thing of someone's hands.

Then again, if a de-cat is cheaper and can be made MOT friendly easily enough I may as well go down that route.

Any advice gratefully received.

StiX

iTrader: (4)

Depends on if you want to retain standard or not.

If so, yes you could probably get hold of a standard downpipe for not a lot.

If you want more power, quicker spool up etc. then decat the downpipe.

For peace of mind, get a freer flowing sports cat downpipe. Scoobyworld are doing a Ninja version for 299. Passes the MOT on its own, you can dump the centre cat.

Or, if you are willing to risk it, just get a normal decat downpipe for about 180, and hope the loophole that worked for me is still there (unsure about this tho - read somewhere may no longer be a loophole).

When I had a 95 WRX last year and tried to MOT it with just the centre put back on, it failed. Then someone told me as its an import and pre Sep 95, then it doesn't appear exactly on their register, so can go throught the non-cat test. Went back to MOT station with this info and it worked!

I have just bought a Ninja sports cat downpipe, should be arriving tomorrow - I'll let you know!! Have just bought a MY00, busy modding it

danno_el_mano

Uh huh. So it does have two cats after all? I was told the centre one was just, quote, a 'resonator'.

Cheers for the tip on the Ninja sports cat too. What about the re-map issues if you de-cat/go for a free-flow version? Will investigate the MOT loophole too - cheers!

And if anyone has an OE system that would otherwise be going in a skip and you live anywhere near SE London give me a shout and I'll take it off your hands! It'll at least get me back on the road while I swot up on all this stuff...

StiX

iTrader: (4)

Always thought there was a centre cat? But could be wrong!

Shouldn't need a remap, but of course it won't hurt. Complete decat will up the boost a bit naturally, and spool up will be a bit quicker.

I had a full decat on my 95, and it definitely spooled up quicker, and boost was up slightly according to my turbo timer (which also acted as a boost gauge).

scoobfan

A JDM WRX Wagon only has the one cat, that's in the downpipe, the
centre you are refering to is a resonator.

Rob

StiX

iTrader: (4)

I stand corrected!

JDM WRX and UK Turbo saloons tho have 2 cats?

Got me wondering now.

messiah

My UK MY00 needed 2 attempts go get through the emissions test with only the downpipe cat - it was less of a problem when the car had warmed up.

KenS55STI

I had a 94 WRX and it had 2 cats. Also had a 1998 STI, 1 cat and 1 resonator.

scoobie-shieldy

my 95 had 2 cats and when i say HAD it no longer does, im now using a revolution 3" thru pipe with a 5" slash box, no remap necessary only d/c battry too reset ecu and she goes like a fast thing on 4 wheels lolz

Walwal

As your motor is a pre 95 import, when you get it MOT'd, it SHOULD get a no cat test anyway. I had big bother with my WRX recently, and after putting the tester on the phone to one of the girls at VOSA, they eventually did the no cat test (even tho mine's not de-catted, still wouldn't pass the cat test, lol).

So if you want to de-cat, then knock yourself out. I think the no cat test CO limit is either 3 or 3.5% (someone will put me right), whereas the original test I had done on mine was 0.5

Hope this helps.

Andy.

danno_el_mano

Cheers chaps - pays to be clued up on this pre-MOT it would appear.

Got a contact with a de-cat downpipe I can have to tide me over. He reckons that + a (pre-warmed!) centre cat would be enough for MOT although I will investigate this theory that, as an early import, it might be exempt anyway. Anyone know of a, cough, sympathetic MOT man around SE London? Don't want to do anything dodgy so just somebody clued up rather than a ticket on the sly...

Chuffing minefield all this but the input is most appreciated! I have a nasty feeling I'm at the top of a long, slippery (and expensive ) slope...

stevo1970

iTrader: (1)

Sorry to hijack the post a little but i want to pick up on something scoobie-shieldy said.

I have a MY00 UK classic, completely standard, I was thinking about removing one of the two cats to free up a little more power and make the turbo spool up quicker. Would this be a waste of time an a standard exhaust? I don't want the car to be loud so a full exhaust is probably not going to happen! Which cat would be the one to remove?
Also as the quote says would I not need a remap after removing a cat or should I just reset the ecu?

Thanks folks

StiX

iTrader: (4)

I have a MY00 which has has centre cat removed, and a Magnex back-box. I have just bought a Ninja Sports Cat downpipe, which is apparently much freer flowing than normal but will still pass the MOT on its own.

Should release maybe 15bhp and spool up a few hundred rpm quicker.

Not sure on effectiveness if you retain the backbox, but you shouldn't need a remap or have to reset the ecu.

I had a full de-cat on my last scooby, a 95 WRX, and even though it had the TD-05 it gave good boost by 2.5k RPM. At the mo with standard front cat, it doesn't seem to give boost until nearer 3k.

danno_el_mano

Walwal - following on from what you said about the non-cat test I checked with VOSA and you're right, they don't have my car on their list as it's an import so it's the non-cat test for me. Cheers for that.

Anyone got any experience of this? A source has told me a de-cat downpipe + (pre-warmed ) centre cat should be enough to get through that - anyone care to comment?

StiX

iTrader: (4)

The non-cat test is a doddle, mine flew it with just the centre cat in and it should do without any cats.

danno_el_mano

Happy days!

Walwal

Did you not believe me?? LOL

No probs mate, glad to help



Andy