de-cat my derv

PAK

Active Member
Sep 25, 2007
54
0
location location
im thinking of having my 2001 ibiza 110 tdi de-cat'd, im not sure if im going to have a full zorst made for it or just take the cat out,at the minute im undecided but i would like to know if removing the cat will cause any problems with the car other than at MOT time? any help would be appreciated
 

PAK

Active Member
Sep 25, 2007
54
0
location location
i thought it might give it a bit of a power gain but other than that i like the sound of tdi's with a SS zorst on, i dont think i'll bother if theres no power gains though
 

devonutopia

fabia-lous
Mar 30, 2004
1,200
1
Exmouth / Exeter
Only power gain to be had might be when you come to do a bit of remapping. ;) Might allow an extra 3 or 4 bhp to be freed up thanks to the less restrictive exhaust. On it's own, it will do sweet fanny adams. :D
 

jonjay

50 Years of 911
Jun 27, 2005
5,843
1
Essex
I left my CAT on and just removed the backbox. Car sounds better and more willing to rev to redline without that massive drop in power at 4k.
 

tan159753

Guest
I always have visions in my head of the cat crumbling up and causing a partial blockage, especially as the mileage steams ahead.

Am i just paranoid or better to get the bugg£r out?
 

mrk

Active Member
May 4, 2007
206
0
I left my CAT on and just removed the backbox. Car sounds better and more willing to rev to redline without that massive drop in power at 4k.

so i take it youve just got a straight bit of pipe then from your centre section to the exhaust tip or is the centre section out aswell

i was told that theres not enough back pressure to run the tdi without a cat

also would the management light not come on?

im surprised that the car passes an mot without a cat lol

i removed my centre section and got a s/s backbox put on, want it a bit louder as its awfuly quiet so i was either thinking about a decat or removing the backbox and just have the cat. ive got a 2001 non pd 110 tdi ibiza
 
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jonjay

50 Years of 911
Jun 27, 2005
5,843
1
Essex
so i take it youve just got a straight bit of pipe then from your centre section to the exhaust tip or is the centre section out aswell

i was told that theres not enough back pressure to run the tdi without a cat

also would the management light not come on?

im surprised that the car passes an mot without a cat lol

i removed my centre section and got a s/s backbox put on, want it a bit louder as its awfuly quiet so i was either thinking about a decat or removing the backbox and just have the cat. ive got a 2001 non pd 110 tdi ibiza
Correct for first question and the management doesnt come on.
 

mrk

Active Member
May 4, 2007
206
0
is your centre section still there

i meant the light would come on if there was a de-cat

what yous think i should do then, remove cat or remove box
 

jonjay

50 Years of 911
Jun 27, 2005
5,843
1
Essex
Yup i'd agree with T Spark with that. Might be a bit loud thats the only thing i would have concerns about.
 

T. Spark

Guest
Yup i'd agree with T Spark with that. Might be a bit loud thats the only thing i would have concerns about.

Oh its very loud under boost mate, far too loud for a day to day car for most, but as its turning into a track day weapon, I dont mind waking up next door with the exhaust note :D

The lightened single mass flywheel at the front makes enough clatter as it is ;)
 

jonjay

50 Years of 911
Jun 27, 2005
5,843
1
Essex
Oh its very loud under boost mate, far too loud for a day to day car for most, but as its turning into a track day weapon, I dont mind waking up next door with the exhaust note :D

The lightened single mass flywheel at the front makes enough clatter as it is ;)
Blimey! :)

We this is one of the reasons why i kept the cat on...noise...Still get better throttle response without the backbox and it does seem a lot more free flowing especially with a remap.
 

T. Spark

Guest
Blimey! :)

We this is one of the reasons why i kept the cat on...noise...Still get better throttle response without the backbox and it does seem a lot more free flowing especially with a remap.

No need to keep the cat just to keep the sound down, Miltek did a de-cat for the MK4 Ibiza, de-cat 2'5 full exhaust with a few silencers and it was no where near as loud as just a mufflerectomy!

I say take the cat out, become hard core and if needs be, throw another silencer in its place :D
 

mrk

Active Member
May 4, 2007
206
0
just off the phone to the exhaust place and they are gonna do me a decat pipe supplied and fitted for £70 gonna keep the cat just incase

getting it done on thursday
 

daveyonthemove

Smile if you like SEAT's
May 14, 2006
1,519
0
Wrexham
I seem to be the only person who has suffered with this, but i'll mention it anyway.
When mine was decatted i found it ran like crap. stalled on hills when cold and needed thrashing to get it to move. Seemed to be gutless in 3rd, and generaly poor to drive.
It felt like a lack of back pressure, but everyone i've spoken to finds this hard to beleive/work out. Anyhow, i put the cat back on within a month and the car ran great again.
I've since changed the backbox and tail pipe, and the car runs much nicer than it did standard and has the same sort of positive effect that people with a decat speak of, but without the probs i had with the decat.
I might have been unlucky, but its worth mentioning :)
 
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