Decat ?

[J4CKO]

Noticed this mentioned quite a lot, as I understand its just removing the catalytic converter and sticking a straight piece of pipe in where it used to go, appreciate it wont pass an MOT and I dont think it is practical on my own car but interested to see if it makes much of a difference from those who have done it.

I did it once on an old Audi 100, a 1990 model as the cat disintegrated but as its not an MOT fail on pre 91 vehciles it was legal, and it sounded fantastic without it !

Has anyone been caught out by it, to behonest I dont care about the environmental concerns as if I did for some reason do it, I only do a tiny mileage anyway and I suspect it would have better emmisions than a lot or cars on the road in that as a petrol it doesnt emit a big black cloud of particles every time I accelerate !

[MX7]

I know of someone who had their cat stolen. They put some pipe in it's place, and it still passed the MoT.

[irf]

I think it makes more of a difference on a turbocharged car then an n/a although I did notice a slight difference on my n/a.

[DanielJames]

I ran decats on both my Saxo VTS' and the Clio 172. Had better results on the Saxo.

was told the Clio needed to be mapped to see the benefit mind.

[Buzzkill]

I prefer my dc2 with the CAT off. I find it sounds marginally better and the throttle response to be marginally better. It also appears to preferable high up the rev range although I'm under the impression at lower rpm it's actually better on/fitted.

[eldar]

I'm all for decatting. Little fkers keep stting in my garden

[Liquid Knight]

Old cars where cat's were restrictive then with better air flow (decent filter), adjusted fueling a de-cat' can be beneficial but on it's own all you're doing is making the car a bit noisier.

Newer cars there is little to no benefit of removing the cat' as the rest of the engine is ballanced to it along side the ecu.

This was covered in detail in last months Practical Performance Car magazine. I think you can view the feature on the PPC website.