Semi De-cat...

12th June 2007, 23:18

Quick one really...
I have a De-Cat pipe where my CAT used to be, underneath the car..
This is fine, but I Still have the Cat by the manifold...
Basically, i can still re-fit my original CAT for MOT's etc, so, would i gain anything by removing the internals from the CAT on the manifold?

ie would it be louder, would i gain power at all?
Or is it not really worth bothering?

David

12th June 2007, 23:36

I dont advise you to do this. The inside components of a catalytic converter are very poisonous. If you dont do the things right you can be very sick.

13th June 2007, 00:31

they contain platinum i think - sell whatever comes out

13th June 2007, 00:31

wait are you saying you had two cats one underneath the car and by the manifold am confused lol

13th June 2007, 00:33

Yeah you shouldnt have two cats down there. And yea the stuff inside a well used cat is apparently worth shit loads, but it makes you ill getting it.

13th June 2007, 00:37

yeah an i think its really difficult to refine the bits out of it you need cause everyone would be doing it otherwise lol

13th June 2007, 08:43

you either have your cat in the manifold or under the car.

13th June 2007, 08:46

Quote:

Originally Posted by Soulless

you either have your cat in the manifold or under the car.

agreed, unless he bought a cat back system for a car with a cat under the car and needs the de-cat pipe to make the extra length??

13th June 2007, 08:52

but then its not semi decat because he still hasnt removed his cat.

13th June 2007, 08:54

i didnt think you could have 2 cats or is that a silencer thats underneath the car???

13th June 2007, 08:55

all he has done is removed his old exhaust and fitted his new one,
furios cats are in the manifold.

13th June 2007, 10:36

Quote:

Originally Posted by Soulless

all he has done is removed his old exhaust and fitted his new one,
furios cats are in the manifold.

Like it can be seen in here:

(picture from our mate jimbo06)

13th June 2007, 11:02

Quote:

Originally Posted by stevcatristicas

Like it can be seen in here:

(picture from our mate jimbo06)

wtf thats one funky exhaust manifold.

13th June 2007, 12:04

I take it thats not a standard Furio manifold?

13th June 2007, 12:06

Just to complicate shizzle, my furios got a cat under the car, and a mk1 fannymould

13th June 2007, 12:07

wtf why?

13th June 2007, 12:14

Lol i dunno. Its craaaaazy

13th June 2007, 12:27

Quote:

Originally Posted by Soulless

I take it thats not a standard Furio manifold?

no

13th June 2007, 12:29

Was gonna say looks a bit beefy;
whats it got a sports cat in it?

13th June 2007, 12:33

something you will have to wait for the owner to exlain, as i dont know why they have done it personally, i think it looks a bit strange, the lower pipe appears to be going off at an angle almost like the car is just gonna have a straight pipe out the side of the car from the manifold

13th June 2007, 14:27

I belive that manifold is the Cituning 4branch manifold for a later VTR which has a sports cat in the manifold, its about £400+ quid but would solve the decat problem as you get the best of boths worlds the better gasflow of a 4branch and the fact you still have a cat.

And before you say it, Yes a total decatted regular 4branch would offer better gasflow but every year youd have to swap manifolds for and after the MoT. This solves it.

Back to the first question,
No Saxo should have Two cats! Check that what you have removed is a cat and not just a siliencer.

13th June 2007, 14:31

yeam am guessing he's just removed the centre silencer thinking it may be a CAT?

13th June 2007, 18:48

It originally had the cat under the car.
I changed the engine when my headgasket went, for a later engine, with the cat on the manifold, meaning i had 2 cats.
I removed the one under the car and replaced with a de-cat pipe, and so now only have the cat on the manifold, which i was thinking of taking the internals out of.
If its poisonous i won't bother.
Thanks
David

13th June 2007, 19:30

Quote:

Originally Posted by DavidKent

Quick one really...
I have a De-Cat pipe where my CAT used to be, underneath the car..
This is fine, but I Still have the Cat by the manifold...
Basically, i can still re-fit my original CAT for MOT's etc, so, would i gain anything by removing the internals from the CAT on the manifold?

ie would it be louder, would i gain power at all?
Or is it not really worth bothering?

David

2 cats i am not sure about that never heard of a saxo with that. are you sure you have not just removed the middle box. On your model i am pritty sure the cat was on the manifold. Yes you can jus remove the can remove the internals of the cat a few of my m8s have done this on there cars. Your car has 2 oxygen sensors 1 b4 the cat nad 1 after the cat. U would have to remove the lower 1 and blank its hole off lower down then tie the sensor up apparently gmc do some part that the lwoer oxygen sensor screws into so u can trie it up. If you dont remove the lower sensor it will proberly put the engine light on as the ecu would not see a cat. I am not sure if u would gain any bhp?

14th June 2007, 00:07

Quote:

Originally Posted by DavidKent

It originally had the cat under the car.
I changed the engine when my headgasket went, for a later engine, with the cat on the manifold, meaning i had 2 cats.
I removed the one under the car and replaced with a de-cat pipe, and so now only have the cat on the manifold, which i was thinking of taking the internals out of.
If its poisonous i won't bother.
Thanks
David

Re- Explained.
As i used my old loom, with the new engine, the lower Llamda sensor has been cut anyway, as there's no need to use it.
Hope that clears things up...

Basically, if its a risky job, there's no point in me doing it, was just enquiring really...
Thanks
David

14th June 2007, 08:27

Best off emailing or pm'ing www.kam-racing.com as they will be able to give the best advice. They can sell you a 4branch manifold and point you in the correct direction on how to change your oilfilter so it doesnt catch on the new manifold, dont worry most R owners have to looking into doing this so its not like its never been done before.

Explain to Kam-Racing that you Originally had a engine which had the exhaust setup with the cat under the car, but have since switched engines to a later engine which has the exhaust setup with the cat in the manifold.

With all the correct facts to hand they should be able to help you out. Its always better idea to replace a item with a performance part rather than try and modifie a factory part to become a performance item.

14th June 2007, 13:19

The two lambda sensors are there to compare if the cat is doing is job. If you remove it and dont remap de ECU, the engine win not run correctly

14th June 2007, 16:30

Quote:

Originally Posted by stevcatristicas

The two lambda sensors are there to compare if the cat is doing is job. If you remove it and dont remap de ECU, the engine win not run correctly

Yes it will on mine.
New engine, old loom and ecu.
Old loom and ecu is meant to have 1 sensor before the CAT, which it does, there's nowhere on my loom to plug a second sensor to, so its simply disconnected.
David