de-cat a imprezza?

Author
Discussion

liamtuscanwayne

Original Poster:

75 posts

260 months

Monday 20th June 2005
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hi got a scooby imprezza and was thinking about de-catting it, is this much work and is it worth it? does it improve performance? is it any louder?

cheers!

vixpy1

42,676 posts

271 months

Monday 20th June 2005
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A decat pipe from hayward and scott is about £105, but not sure if you need one of thier back boxes as well.

Yes, it improves performance.. its not much louder unless you have the backbox as well..

Well worth it.

Hanslow

813 posts

252 months

Tuesday 21st June 2005
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The centre pipe is about 105 quid, the downpipe is a little more. Also depends on what model year your Impreza is. As the later ones also had an uppipe. The classics have a 3 part exhaust (downpipe and centre both have cats, back box doesn't) and the newer ones have a 4 part exhaust.

From memory, fitted, I think my downpipe was around 300-350, centre around 100-120. Allegedly put the bhp from 215 to around 240 (allegedly ). With the downpipe cat gone, spool up is louder and felt quicker. Those days are gone though as I moved from Scooby ownership a while back.

It will fail the MOT though, unless you put the centre section back in and make sure it's warmed up enough before the emissions test.

Edit: Just looked at your profile and you have the bug eye model so you probably have 4 part exhaust. There is certainly a cat in the downpipe (biggest gains from removing that but also puts your emissions up the most when removed) and a cat in the centre. I think there might also be a cat in the up-pipe but not sure. Definitely louder and feels faster

>> Edited by Hanslow on Tuesday 21st June 01:13

tuttle

3,427 posts

244 months

Tuesday 21st June 2005
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Decatting ought to equate to *free* power gain.Agree 100% with above posts regarding emissions,so keep your old cat to swap in & out for MOT time.
Easy job to do, really just swapping a pipe with a bulge for a straight(ish) bit if pipe.Prob a good idea to take some care with removal tho,due to the heat & corrosion etc that goes into an exhaust system the studs can become brittle & snap off.-and you really don't want that

vixpy1

42,676 posts

271 months

Tuesday 21st June 2005
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If you pop the car down to Hayward and scott, they will pop it on for free, when you buy it.

rustybin

1,769 posts

245 months

Tuesday 21st June 2005
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If you do have the de-cat done it may be worth going to an Impreza specialist come MOT time. I have heard that despite their detailed knowledge of the car they sometinmes get confused and put the sensor in the wrong exhaust. Easy mistake to make with so many cars hanging around at the same time I guess

shadowninja

77,503 posts

289 months

Tuesday 21st June 2005
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That's one mother of a rear spoiler. Can't imagine the drag it must create

tuttle

3,427 posts

244 months

Tuesday 21st June 2005
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Nah! he's been to see the new Batman movie!
Its a boot airbrake (& matching gazebo) -also for cooling mega-wattage subs.


>> Edited by tuttle on Tuesday 21st June 17:37

Mr E

22,128 posts

266 months

Tuesday 21st June 2005
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De-Cat a turbo car?

Do it. The difference it made to my turbo spool up was worth every penny.

Beefmeister

16,482 posts

237 months

Wednesday 22nd June 2005
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You might want to learn how to spell ImpreZa before modding yours.....

But as has been said before, head to Hayward & Scott, Burnt Mills, Basildon.

They do amazing work there.

dnb

3,330 posts

249 months

Wednesday 22nd June 2005
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A classic shape Impreza will get through its MOT with just the centre section cat in place, provided the car is warmed up first.

Easy to change too...