DECAT, worth it or not?

Hi guys,

Just a quick question. Is it worth fitting a decat? is there much of a performance difference? any sound difference? and would it cause running issues?
 
Hi guys,

Just a quick question. Is it worth fitting a decat? is there much of a performance difference? any sound difference? and would it cause running issues?

You wont gain much on an NA car to be honest. It makes a noticeable difference on turbo cars though.

Youll probably get a noticeable flat spot around 2.5-3k revs, a remap may help with this. Not sure about noise though, on my Volvo it doesn't make a huge difference but I have the oem cat back exhaust.

regarding running issues, you'll probably get an EML coming on. I'm not sure how people get round that, maybe a spacer on the lambda or a remap to take the second lambda out.
 
I've got an Akrapovic Evo exhaust which deletes the cat. I can't comment on the sound of a decat alone obviously but if you look HERE there should be a couple of videos somewhere.

I doubt there will be much of a performance difference.

I don't have any emission fault lights or anything on my dash with my Akra and it flew through the MOT :smile:
 
So really its not worth getting rid of the cat then?? as it wont really give any performance gain and may cause issues, flat spots etc,
is a sports cat any better?? any performance gain or is this the same as decat..
 
So really its not worth getting rid of the cat then?? as it wont really give any performance gain and may cause issues, flat spots etc,
is a sports cat any better?? any performance gain or is this the same as decat..

I wouldnt bother with either, just leave it unless your going to get it mapped. May have MOT issues having a cat missing too.
 
I wouldnt bother with either, just leave it unless your going to get it mapped. May have MOT issues having a cat missing too.

Clio has two cat's does it not? Heard of most people taking out one cat and still passing MOT with flying colours!
 
Yeah that's why I said maybe. Depends on how much of a stickler the tester is I guess as it's still got one missing.
 
Yeah that's why I said maybe. Depends on how much of a stickler the tester is I guess as it's still got one missing.

Hope the tester is in a good mood that day :thumbsup:


However would the decat not remove both or would it just basically be deleting one?
 
Yes, as all the above have said, a decat will remove just the second (main) cat. There is a cat in in the manifold too, some people have removed this also by changing the manifold. You should still pass an MOT unless the tester realises that the car came with 2 cats (unlikely).

Unfortunately I have to change my downpipe and decat back each year for the MOT as with it removed i have a straight pipe from the turbo to the backbox, but it's a fairly quick and easy job.

I wouldn't bother personally, I did it on mine as it could be as much as 15hp difference for me, but on your car you're probably looking at 1 - 2hp at most.

A sports cat will give even less of a performance increase so unless you have an issue with your current cat, leave it as it is.
 
Yes, as all the above have said, a decat will remove just the second (main) cat. There is a cat in in the manifold too, some people have removed this also by changing the manifold. You should still pass an MOT unless the tester realises that the car came with 2 cats (unlikely).

Unfortunately I have to change my downpipe and decat back each year for the MOT as with it removed i have a straight pipe from the turbo to the backbox, but it's a fairly quick and easy job.

I wouldn't bother personally, I did it on mine as it could be as much as 15hp difference for me, but on your car you're probably looking at 1 - 2hp at most.

A sports cat will give even less of a performance increase so unless you have an issue with your current cat, leave it as it is.


Ok ok mate so I am just going to go with a cat back system I think