1.8T Decat.


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Feb 5, 2009
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How much does the Decat actually effect the car.

And is it advisable to do before a Remap?

Thanks, Ryan

P.S Does anyone have one for sale?
it's not so much the standard cat that's an issue at all, the cat isn't really restrictive.

the problem is the size of the standard downpipe.

If you were to cut the cat out of your downpipe and replace it with a straight pipe, I doubt you would see any improvement at all.

But, most decats are sold as a decat/down pipe seeing as the standard unit is a single intergrated part.

Adding a larger 2.5 or 3'' downpipe will make a big difference to how the turbo spools up, it;ll spool up sooner and much faster, and it'll free things up at the top end too.

If your car has an AGU engine, which I think it does, fitting a decat isn't a problem at all, as you only have a pre cat lamda sensor, unlike the later cars which have both a pre and post cat lamda and will throw a fault code without a cat in place.

I'd go for the THS down/pipe and decat available on ebay, it's only £100, and fitting is dead easy.

THS also have a website www.thsperformance.co.uk, but for some reason the decat isn't listed.

It's good quality stuff, and several forum members have one and have no complaints.

As soon as I've got the cash, I'm swapping my dying milltek downpipe/sports cat for a THS decat.
thanks for the quick reply Prawn.

I think i will buy a THS decat, but on the picture it has a pre and post hold for lambda. would i jsut get a bung for the post hole?
Just about all decats have holes for both pre and post cats mate, most come with a bung to plug the post cat hole.

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