Right, I've been toying with this idea for a while now and can't decide whether a decat is worth it?

I've found an off-the-shelf pipe to fit with an adaptor to fit the standard bore centre section so all good on that front. I basically wondered if anyone could give any kind of overall review of how the engine responded if you've done it to your TDI?

I was just about to order it tonight after not really hearing any bad things about it, but found a topic on the uk-mkiv forum saying it takes away the initial 'kick' when the turbo starts doing its job! I love the punch that the octy has now it's remapped and don't know if i would just be a bit annoyed if i spent money on a decat which took that away.....

Before now as far as i could see the pro's outweighed the con's. not so sure now.

advantages: quicker spool up & turbo noise

disadvantages: lack of 'kick' & feeding the trees with more carbon dioxides

I fitted the whole miltek system to my mapped pd130, I can't comment on the decat along but the whole system smoothed out the map a little but did increase ftlb & bhp.

I've just fitted a plain decat pipe to my pd140 and it too has helped smooth out the map but didn't give any extra ftlb or bhp.

The spool up is a little quicker and the noise is slightly boomier but I'm sure that will die down a little when it gets a little layer of soot inside.

Ive got one on my re mapped PD but ive got a 63mm system all the way through so i couldnt comment on just the de cat with the original 57mm system but for me its added bags of torque and smoothed the map out lovely.

You dont get the intital kick, which is a good thing because that is basically lag waiting for the turbo to over come the back preasure or having the cat in the exhaust, without it the turbo is free to spool up hense a smoother drive.

Id say it was worth it, removing a cat on any car is always worth it and as its a re mapped diesel everything is in your favour

Thanks for both your replies - Just ordered a THS downpipe!

Which milltek systems did you guys fit? I like the idea of the bora discreet box but always wondered if the bora cat back system is a direct fit, or whether you have to use the octavia centre section with bora back box?? Anyone able to point me in the right direction for this?

Unfortunately the rest of the system will have to wait until funds allow. Plus, an Oil change takes the next priority....

I used the Jamex cat back system its designed ti fit onto a standard exhaust thus had a step down to fit the OEM cat but to fit this to the miltek down pipe you get a sleeve that comes with it and all you do is cut the step down off and then you get a straight 2.5 inches all the way through.

The only - point with the system is as its designed for a VRS its as quiet as the original system, give or take but i didnt mind that to be honest, a bit of noise wouldve been nice but it coulve been worse it couldve been round the other way

Thanks for both your replies - Just ordered a THS downpipe!

Which milltek systems did you guys fit? I like the idea of the bora discreet box but always wondered if the bora cat back system is a direct fit, or whether you have to use the octavia centre section with bora back box?? Anyone able to point me in the right direction for this?

Unfortunately the rest of the system will have to wait until funds allow. Plus, an Oil change takes the next priority....

I bought mine from Awesome, the whole system was for the Bora (I believe) with discreet backbox, I also ran the resonated system so in normal driving conditions it was a quiet as standard however when you pressed the loud pedal it sounded great

Original Cat

Decat

Discreet Backbox

And to answer your 1st question, Is a Decat worth it? I've just bought a decat for my current Octavia TDi

from experience, dont' throw away the original cats you'll need them for the MOT:)

from experience, dont' throw away the original cats you'll need them for the MOT:)

Dont need it on a diesel! only on a petrol car as a diesel only gets a soot test

Again thanks for the replies! Looking forward to getting the decat fitted now, and almost definitely going to be investing in the bora cat back system at some point - thanks for the pics matt@theforce!

from experience, dont' throw away the original cats you'll need them for the MOT:)

Even though it's not needed for MOT I wouldn't throw a cat away anyway - worth too much!! :p