I finally went ahead and got the catalytic converter removed on my Fabia vRS. Followed Ross's advice found on another thread and got the cat section torched off and a section of straight pipe flared and fitted with a MIG welder. Left the original backbox as is.

Got this done professionally at a well-known exhaust place here in Bahrain while I waited for the princely sum of GBP 13.80!!!!

Findings? :

MUCH smoother in the power delivery throughout.

Less drop in revs between changing gears on hard acceleration.

Turbo Lag virtually gone now.

A little more turbo whistle can be heard.

Barely any change in exhaust note, no noticeable increase in volume at all.

More low-end torque, evidenced by having the car lurch forward when changing gears in the same manner as before the de-cat.

Less exhaust smoke on accelerating hard. Still the magic cloud if you keep it in too high gear while booting it:thumbup:

Smoke smells "dieselly" now - no longer sanitized! More of an offensive weapon when "smoking" people:rofl:

Overall - I'm well pleased.

Oh and BTW the MOT doesn't require a cat for diesels in the UK AFAIK.

Cheers

Bas

6. Your vehicle has had its catalytic converter removed and replaced by a normal exhaust silencer but passes the emissions Test. Does it fail the MOT because it hasn't got a catalytic converter when it should have one?

a) No, if it passes the emissions part of the MOT that is acceptable.

One important issue must be cleared up straight away. There is no requirement for a catalytic converter to be fitted to any vehicle, regardless of its age. It is however the most popular way of ensuring engines meet the emission legislation. The MOT test is testing the emissions from the tailpipe and if those emissions meet the standard then the vehicle passes. The term 'cat' test is inappropriate, the correct term is 'advanced emission test'. Its not the 'cat' that's being tested. There are a number of vehicles which are subject to the 'advanced emission test' but are capable of meeting the requirements without the use of a catalytic converter.

Sounds interesting

Diesels are not currently test for "emissions" just smoke particulate, so yes running your VRS without a cat is not going to led to it failing its MOT.

6. Your vehicle has had its catalytic converter removed and replaced by a normal exhaust silencer but passes the emissions Test. Does it fail the MOT because it hasn't got a catalytic converter when it should have one?

a) No, if it passes the emissions part of the MOT that is acceptable.

One important issue must be cleared up straight away. There is no requirement for a catalytic converter to be fitted to any vehicle, regardless of its age. It is however the most popular way of ensuring engines meet the emission legislation. The MOT test is testing the emissions from the tailpipe and if those emissions meet the standard then the vehicle passes. The term 'cat' test is inappropriate, the correct term is 'advanced emission test'. Its not the 'cat' that's being tested. There are a number of vehicles which are subject to the 'advanced emission test' but are capable of meeting the requirements without the use of a catalytic converter.

Sounds interesting

I would be surprised if anything is being tested, Basil is in Bahrain useful info though

Interesting thread. Not that I am going to decat the Furby, but should I buy a TD out of warranty sometime...

Also, I dont think you have to have a cat on any car pre-1992 although some have them fitted.

My 1990 CRX VT was decatted.

As for the 'no car has to have a cat but must pass the emissions' I am quite curious now as to which cars are likely to pass emissions with no cat fitted...

interesting thread...

I thought I read somewhere that problems can occur when there is no back pressure from removing the cat?

I thought I read somewhere that problems can occur when there is no back pressure from removing the cat?

There shouldn't be any problems..

I thought I read somewhere that problems can occur when there is no back pressure from removing the cat?

I'd heard that too.

Over on TDICLub.com they say the turbo gives enough back pressure. Over there they just run a straight through pipe like Jason.

I've just tried to read some review's from the said website about running a de-cat. But it's down as far as my internet is concerned.

Back pressure issues as a result of removing cats only seem to be a problem on NA motors (from what I have read on tinternet)

Basically - a TDI turbo produces enough back pressure to not need an exhaust at all (in theory) I've at least got a straight pipe going to my tail, but sometimes I wonder I need bother with anything more than a bit of pipe going from the turbo and exiting behind a front wheel?

Going to get my Allard downpipe fitted this Saturday all being well, so looking forward to seeing how that little addition affects my motor.

Basically - a TDI turbo produces enough back pressure to not need an exhaust at all (in theory) I've at least got a straight pipe going to my tail, but sometimes I wonder I need bother with anything more than a bit of pipe going from the turbo and exiting behind a front wheel?

Going to get my Allard downpipe fitted this Saturday all being well, so looking forward to seeing how that little addition affects my motor.

Fitted yet? Was looking at this for mine as part of the build up to the new turbo etc. would be interested to hear feedback. Allard are well cheap on most stuff compared to JBS and Jabba - just discovered this when i rang them last week.

IMO...and after reading through recent turbo failure threads....

Two things can happen after you decat that aren't turbo friendly, you'll get boost spikes as the algorithm used to manage it isn't set-up for a totally free exhaust. Also, there's the danger of the turbo overspeeding.

I think if you're remapped/tuning boxed and have freed up the induction too, you're more at risk as airflow variations through the engine can be more aggressive.

Just my 2p.

J.

Fitted yet? Was looking at this for mine as part of the build up to the new turbo etc. would be interested to hear feedback. Allard are well cheap on most stuff compared to JBS and Jabba - just discovered this when i rang them last week.

It is fitted now, but its actually had a slight negative effect. I put this down to the remap being done on the old peashooter, and now I have a full 2.25"+ system.... The turbo does spool up nice now, but in the mid range, it's not quite got the same kick. Only option I really have is renew some more hardware, and then go for another fresh remap. Then NOT change anything else....

The wooshing noise has been curtailed a little bit by the downpipe (i guess the noise was air being forced through the tiddly 1.75" oem downpipe?) and there is now a nice tickover rumble in addition. Sounds nice in action as well, although I think with another remap/turbo it will sound even nicer.