De-Cat

KevMayer · Unread post by **KevMayer** » 29 Sep 2004, 04:37

My middle exhaust pipe has corroded. My local Citroen man says I should have a new Straight through pipe, instead of a pipe with a Cat.
This should give me a few more Bhp. Does anyone know how much more i should expect by de-catting in this way.
The car is a 96 1.9 turboD Xantia.

JohnD · Unread post by **JohnD** » 29 Sep 2004, 11:40

The test results for a 1.9TD in 1995 give a BHP figure as 92 and a Govt MPG figure at 43. By 1997, when they'd added a cat and EGR, the figures had dropped to 90 and 40.

Kowalski · Unread post by **Kowalski** » 29 Sep 2004, 14:44

I decatted. MPG Improved by 5 mpg. More importantly low down torque improved.

Stuart McB · Unread post by **Stuart McB** » 29 Sep 2004, 15:13

Can a car made with a CAT be MOT'd with out it? Just spoke to a mate who's a soilicitor and the advice given before they asked for payment (damn solicitors)If it meets the legal requirements on omissions then it's fine and will pass but if it don't then you'll ned to sort it out by adding the cat back. Seems straight forward to me, but on a 96 car how are the ommissions going to be? Or do we have the smoke test instead like the petrol test? Sorry but a blank face and "I haven't got time for this" from my mate.

VisaGTi16v · Unread post by **VisaGTi16v** » 29 Sep 2004, 15:22

I thought if the car was sold with a cat for its year of er birth(???) then it has to have one but on the other hand, no mot person will know if it was around the time they were bought in by law, ie 1993 or something. If you have a later car they may fail it instantly or more likely, not notice and if the emissions are low enough it will just pass.
I dont get emissions anyway. My zx 16v with its cat has struggled the last 3 years, took about 30 minutes last time! my visa with its bx 16v, no cat, just 1 rear silencer sailed through??

Unread post by **RichardW** » 29 Sep 2004, 16:58

No cat required on diesel engines at the moment - only test on emissions is smoke opacity (and STILL HMG tries to convince us they are dirtier than petrols....??)
So as long as your environmental conscience allows - remove it!

Richard Gallagher · Unread post by **Richard Gallagher** » 29 Sep 2004, 23:56

De-catting has worked for me for since my Xantia was 6 months old, never a hint of a problem at MOT time.

JohnD · Unread post by **JohnD** » 30 Sep 2004, 00:30

Although the same engine was going into both Xantias and 406's, the Pug had a cat/EGR fitted a full year before the Xant.

nick · Unread post by **nick** » 30 Sep 2004, 02:28

Strictly speaking, in the UK if a diesel was originally fitted with a cat, then by law it is supposed to continue to have one. However, the police, central government, and MOT testers currently do not have any central records of which diesels had one and which didn't, so the law is unenforceable in practice.
I asked my MOT tester recently whether they check for the presence of a cat on diesels. He said they weren't bothered at all if it had a cat or not, merely whether the car was capable of passing the smoke test, which the cat makes little or no difference to anyway.

paranoid · Unread post by **paranoid** » 30 Sep 2004, 10:11

Does anyone know where to get an off the shelf de-cat pipe?

JohnD · Unread post by **JohnD** » 30 Sep 2004, 11:16

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by paranoid</i>

Does anyone know where to get an off the shelf de-cat pipe?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
My local accessory shop keeps a catalogue of exhaust systems with diagrams of each model of car. Try to get a look of one and see what's available for Xantias of around 1995/6.

Kowalski · Unread post by **Kowalski** » 30 Sep 2004, 16:00

You don't buy a de-cat pipe, you just buy a front pipe for a Xantia that didn't have a catalyst...
Jon, I'm sure will be able to quote the part numbers for both the estate and hatchback.