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Old 20 September 2003, 12:18 PM
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Mr Merciless
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I thought it was illegal to remove the cat as it sends your emissions throught the roof?

I take it you put it back on when it's due for mot?

And wont the police do you if you get caught? Also does it ruin warranties etc?
Old 20 September 2003, 12:25 PM
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ALi-B
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I take it you clicked new topic instead of reply
I let you off as your a newbie

Anyway, yes if you have a full decat (take off all the cats) then yes it'll most likely fail.

Exceptions are my old XR3 16v which was decatted after it shattered and blocked the exhaust (that's the excuse) to my amazement it passed!! (only just though) normally would take 2/3 attempts but it did pass

And yes I do fit a cat to my scoob for MOT


[Edited by ALi-B - 9/20/2003 12:26:32 PM]
Old 20 September 2003, 02:38 PM
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jpor
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Currently running my with the one cat in place on the down pipe. The centre cat has now been removed. And boy what a difference it made.

Been reliably informed that on most classic scoobs that they are fitted with 2 cats. And just running on the one still allows for it to pass the MOT emissions tests in the UK.
Old 20 September 2003, 02:45 PM
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Mr Merciless,
Yes it is illegal to run your car without a cat, i think its any car that had a cat on after 1989 and all cars after 1993.
Also depending on which model scoob you have (ie a classic or a bugeye) depends on how many cats you have!.
Most JDM cars just have a cat in the downpipe, as stated, classics have 2 cats, 1 in the downpipe and 1 in the centre section, bugeye wrx's have 3 cats, 1 in the up pipe, 1 in the downpipe and 1 in the centre secion, the MY01 onward STi's have 2 cats, 1 in the downpipe and 1 in the centre section.
There is a lot of difference when you remove these, more boost, more power, more noise and yes, supposedly more emissions
If you get caught without a cat, you have 7 days to get one back on and tested, then (i never told you this ) you can take it back off again

Tony
Old 20 September 2003, 05:34 PM
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Question

i wonder how many old bill come on here and read wot we say!!!lol
Old 20 September 2003, 05:45 PM
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I have a MY03 with PPP Not sure how many cats I've got
Old 20 September 2003, 05:56 PM
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Supercue,
They remove the centre cat when fitting the PPP and replace it with a baffle box (so 2 cats)

Tony
Old 20 September 2003, 06:01 PM
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Supercue
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Tony is that 2 cats left on the downpipe?
Old 20 September 2003, 06:04 PM
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Fatman
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No, he means that the car looks like it still has the two cats it was supplied with.
Old 20 September 2003, 06:08 PM
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Supercue
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Sorry for sounding so ignorant as you can see I'm no mechanic when it comes to Scoobys :-)

I would like to de-cat it completely has anybody got an idea of cost and the best way to go about this?

Answers on a post would be grand
Old 20 September 2003, 06:18 PM
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Supercue,
The MY01 onwards have 3 cats, they remove the one in the centre section of the exhaust, the other 2 are in the up pipe (above the turbo) and in the downpipe (below the turbo).

Tony
Old 20 September 2003, 06:26 PM
  #12  
Fatman
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To fully decat an MY03 you need to fit a straight-through centre section and a straight-through downpipe.

Have a look in the Exhausts section of the ScoobyShop for new parts. Decent brands to consider include ScoobySport, Hayward and Scott (H&S). There's a wide variety of sounds and noise levels available - these two won't deafen you, though .

Alternatively, try and pick up a cheap 2nd-hand part from the For Sale forum. I didn't see any in there right now, but it's quite common to see exhaust parts advertised.

You could also try posting in the Wanted forum, and let the seller come to you!
Old 20 September 2003, 06:53 PM
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Chris29
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There's a few of us 'old bill' who read what you say!!!!!
I aint getting down on my hands and knees in the middle of Longsight to see if you've de catted your scooby mate, sorry, call me negligent but i aint. As for the seven days, its no secret, its called Vehicle Defect Rectification Scheme and is part of a producer. You have seven days to get an mot station stamp to say work has been done. I do it to taxi's all the time as it really bugs em!!!!! (malicious giggle, wringing of hands!!)
Old 20 September 2003, 07:00 PM
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Tony - IIRC, it's only the bugeye WRXs that have the up-pipe cat fitted as standard. They took it out again for the MY03 onwards. I suspect that's the main reason that the MY01-02 is generally thought to be a bit "flat" compared to the classic and the MY03.
Old 20 September 2003, 07:07 PM
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Lightbulb

And an alternative option to the original poster- you can get sports CATs, which are in theoretically emmissions friendly enough to get you through MOTs etc, so therefore legal. Prodrive do this in the PPP for the STi. Other options that spring to mind are Power Engineering (sports catted centre), APS (which I like, having one myself), Milltek, I think scoobyworkd do too, and I'm sure there are others.
Old 20 September 2003, 07:19 PM
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so where u based at then chris29? and do u own a scooby yourself or are you just on here snooping? :P
Old 20 September 2003, 08:55 PM
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Angry

X8
Old 20 September 2003, 09:02 PM
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i have a 97 uk scooby and just wondered if i was right in thinking that i also have 2 cats , 1 in the d/pipe and 1 in the centre section? please advise. paul
Old 20 September 2003, 09:35 PM
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yeh thats right m8...so long as you aint taken none out!!!lol
Old 20 September 2003, 09:58 PM
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ianmiller999
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This is a curiosity post, what sort of gains can be expected from removing CAT, bhp/torque?
Old 20 September 2003, 11:45 PM
  #21  
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Supercue - if there's only a cat in the dp then you're looking at around £220-£250 for a straight through dp plus around £85 fitting. Hayward & Scott are a popular brand with scoobs. There's loads of others though incl Janspeed, Scorpion, Miltek, HKS.

Ianmiller999 - gains might typically be 30-40bhp for a full system (downpipe, centre and back box). I think dp gives highest gains, then centre then BB. If you then get a remap you'll further benefit from the new system. Turbo is said to spool up much earlier in the rev range, making the car more driveable.
Old 20 September 2003, 11:46 PM
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Talking

Cornerrrrrrrrrrrrrrrr
Old 20 September 2003, 11:48 PM
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Cheers slowboy will pop down to Extreme and found out the full costs
Old 21 September 2003, 12:03 AM
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How come if any other illegal behaviour is talked about on here the moderators delete it. This should be treated the same. You bastrads are giving my kids asthma with your decats. If you can't afford a car thats quick enough without having to make it illegal then **** off [img]images/smilies/mad.gif[/img]
Old 21 September 2003, 12:28 AM
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I'm after a Blitz NUR R spec system for me 93 wrx, but which downpipe shud i get to go with it? any1 know!?!?! oh an wheres the best deal for me Blitz system they seem to be knockin about for £550?
Old 21 September 2003, 08:50 AM
  #26  
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.....How come my Standard (March 2000) UK Classic Turbo had only one factory fitted Cat in the downpipe. It has no Cat in the Centre section? Anyone else come across this? The centre section is definately factory fitted and not a modification. I thourght all UK spec turbos had two Cats?
Always thourght my standard Scoob was a bit more nippy then the average!....anyway at least i'm smiling since my H&S d/p went on.
Old 21 September 2003, 09:06 AM
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@ Scoobydick: as far as I understand it, asthma is aggravated by carbon particulates. Catalytic convertors don't target particulates, they convert gases of one type to another. Heavy diesel engines emit lots of particulates (think taxis, old HGVs, buses, etc). Tuned Imprezas, AFAIK, don't tend to emit huge quantities of particulates. The high quality of fuel used in these cars (Optimax, Super Unleaded) probably helps with this.

Please - if someone knows better than I - do correct me.
Old 21 September 2003, 10:38 AM
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Exclamation

Superdick if you studied pariculates you would know that just 1 Jumbo jet puts far more contaminants into the atmosphere on take off than all the scoobys in the UK.

Old diesals by far cause more asthmatic related conditions than a scooby any day of the week.

Old 21 September 2003, 01:58 PM
  #29  
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I'd suggest the 40bhp end of the power gain spectrum is a little bit ambitious, 25-30 is probably more typical. It's the spreading of the power that makes the big difference - turbo spools up earlier, power continues on for longer.

IIRC, catalysts main "job" on a petrol engined car is to reduce the output of Carbon Monoxide and unburnt hydrocarbons, resulting in more Carbon Dioxide (a greenhouse gas), and water instead. Particulates aren't a big issue with modern petrol engines. It's also true that cats tend to worsen fuel economy.
Old 21 September 2003, 06:14 PM
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"How come if any other illegal behaviour is talked about on here the moderators delete it. This should be treated the same. You bastrads are giving my kids asthma with your decats. If you can't afford a car thats quick enough without then **** off"

1. The moderators don't always delete so called illegal behaviour!
otherwise there would be no "racing" threads.
2. "FATMAN" is so right in his supposition.
3. Are you so illiterate that you have to resort to so many expletives in one sentance?
4. No, I've got bored of chastising you now, you boring,self righteous, blinkered Philistine.
dave
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