Decat vs Sports Cat

[Martin.]

Both are technically illegal apparently. Anyone object to that statement?

If they were the same price which would you go for and why? I know my mate went for a decat simply because he was skint and didn't have the money to buy a cat!

Was planning on getting a Milltek sports cat. But the company have told me that even though it'll pass an MOT it's not technically legal and is for Motorsport use only.

Think the standard cat lets though about 45-50% volume, sports cats let through about 75-80% volume, and I'm assuming a decat lets through a 100%. Please correct me if I'm wrong.

The reason I was planning on getting a sports cat rather than a decat. Even though I want what's ultimately best for my track car. Is because I don't want the minimal hassle of taking it on and off for the MOT. And I do not want the VERY VERY small risk of being pulled over by the police or whoever and being done for not having a cat.

But now I've been told that the sports cats are technically illegal anyway the only real reason for stopping me going for a decat now is the minimal change over hassle come MOT time.

What's the risk of running a decat? Is it that much better for the car to be worth it?

It will VOID insurance if not declared obviously, but do the modified policies even allow it?

Will I constantly have an emission light on the dash with a decat? Obviously I will plan to get it all mapped properly once done anyway.

Anything you can answer for me or point out will be great. Please discuss.

Cheers

 

[Westytce]

With illegal changes declared I'm sure insurance won't touch you. Remember they are regulated and share information. If a sports cat passes mot parameters the car is road legal?

Me I'd put sports cat in, save some trees and ozone layer and your not going to be in any stink when mot time arrives.... Love the ministry.... Hmmm

 

[Chip-mk1]

I object to the statement about both being illegal, tehy certainly arent to the same extent (although like ANY mod they risk breaching type approval) on what grounds is a sports cat illegal specifically though?

Decat obviously means you will fail emissions, so I understand that one, but not a problem with a sports cat.

 

[Westytce]

I object to the statement about both being illegal, on what grounds is a sports car illegal?

Decat obviously means you will fail emissions, so I understand that one, but not a problem with a sports cat.

Thats the op statement not mine...

 

[Chip-mk1]

Thats the op statement not mine...

I was replying to the OP, he said to say if you object, so was just saying I dont agree that they are "equally" illegal.

Edited my reply to be clearer but obviously must have done as you were quoting it.

 

[Martin.]

I agree. I've never heard of a sports cat being illegal. I always assumed if it could past an emissions test then it was fine.

But speaking to a Milltek distributor and he said it's technically not legal. No TUV or something? But also that it was very very unlikely that anyone would inspect it enough to find out. So as long as it passed the emissions test no one would technically know it was made differently.

EDIT: Sorry this is what he replied, saying "It will pass on emissions, but only if they look inside the cat they will see its not 100% correct"

 

[Chip-mk1]

TUV is of NO relevance in the UK whatsoever legally speaking that I am aware of.

You are changing your car, therefore you break the type approval, but thats true of a whiteline ARB or a set fo coilovers or 4 pots etc too.

 

[Martin.]

Do you run decats chip?

 

[Chip-mk1]

Do you run decats chip?

I have done on some cars (of the cars I have at the moment I have them on 4 of them in fact), our RS2 one currently runs a sports cat though, but hasnt been for an MOT since fitting it so I have no idea if it will pass or not.

 

[Chris_ZS]

Decats can be insured, you can tell your insurance fine, Skyinsurance will tell you that. Its up to you to have your car road legal. But they'll insure the car with it.

I'd run sports cat, the difference is far to small to have the hassle of worrying about decat, I ran one with my fiesta for two years but i'm quite happy to have a cat/sports cat nowadays just as its easier for MOTs and if you were ever to get the VOSA check up

 

[Martin.]

I'd be very surprised if the sports cat didn't pass the MOT. That's the reason they are made isn't it? So to fail at that almost make their existence worthless, almost.

Can you still get insured declaring a decat? Obviously would have to be a company with a modified policy..

 

[Martin.]

Decats can be insured, you can tell your insurance fine, Skyinsurance will tell you that. Its up to you to have your car road legal. But they'll insure the car with it.

I'd run sports cat, the difference is far to small to have the hassle of worrying about decat, I ran one with my fiesta for two years but i'm quite happy to have a cat/sports cat nowadays just as its easier for MOTs and if you were ever to get the VOSA check up

This is what I'm thinking. Not worth the hassle etc.

 

[Goodj]

so long as it passes emissions, how can it be illegal?

And if insurers will cover them, or at least not bum you for it, then why not.

 

[Martin.]

of the cars I have at the moment I have them on 4 of them in fact

How many cars do you have lol show off!

 

[Chip-mk1]

I'd be very surprised if the sports cat didn't pass the MOT. That's the reason they are made isn't it? So to fail at that almost make their existence worthless, almost.

Depends if its still in good condition or not, I bought it as a pair with a 182 manifold as I swapped from a 172 one when I rebuilt the engine.

Can you still get insured declaring a decat? Obviously would have to be a company with a modified policy..

I dont have to declare mods as I have a blanket trade insurance policy, but I know of people who have listed it on their policies and not had a problem, which is weird when you think that is them essentially making a statement that their car is not road legal!

 

[Chip-mk1]

How many cars do you have lol show off!

11 at the moment, but I dont ever have them all on the road at once, I cant afford the tax, lol
We normally have about 5 or so on the road generally.
At the moment the only ones I have on the road are a rather unexciting list of:
Mk1 clio
Ph1 172 turbo
Ph1 172 clio
RS2 172 clio
Corsa 1.2

All the interesting stuff is SORN currently, and most of it is only half built!

 

[Chris_ZS]

Insurers will list it because its your car and up to you to ensure its road legal.

Whether they will actually cover it or not in a bump is another story.

 

[Martin.]

so long as it passes emissions, how can it be illegal?.

This is my point

 

[Chip-mk1]

Insurers will list it because its your car and up to you to ensure its road legal.

Whether they will actually cover it or not in a bump is another story.

If you have a bump though, how do they PROVE that your car woudlnt have passed emissions before the bump with a decat in place.
Its a bit of a strange situation, we all know it woudlnt, but thats not the same as it actually failing.

 

[Keyser Soze]

so long as it passes emissions, how can it be illegal?

And if insurers will cover them, or at least not bum you for it, then why not.

New rules state if it was fitted at the factory then it has to remain in place.

 

[Goodj]

New rules state if it was fitted at the factory then it has to remain in place.

Fair enough.

If the legs apply retrospectively then so be it.

 

[Chip-mk1]

New rules state if it was fitted at the factory then it has to remain in place.

To what extent does it have to "remain in place" though? What happens when it dies and needs replacing?

Lots of people run non genuine renault cats, so long as they are equivalent, and in fact I suspect under EU it would acutally be illegal for any government to stop you running aftermarket parts as it would be anti competitive.


We are in a weird situation at the moment that our cars are type approved when new, and unless they are modified a lot and hence need an SVA/IVA etc then they dont then get tested for specification again, the MOT only tests for condition.

So lots of things are "kind of" illegal, but there is no definitive test for.

 

[Goodj]

lots of things should be illegal, as crimes to society.

#yozza
#stance
#replica

 

[Chip-mk1]

And grown men driving around in girly mx5s

 

[Martin.]

LOL

 

[Goodj]

And grown men driving around in girly mx5s

good thing I've got one with man-spec then

 

[domjolly]

grey area for decats the item themselves are not illegal and having them fitted is not illegal, i also had mine declared on my insurance through sky on here. The issue with decats is that your car wont pass an emmisions test which then makes the car unable to pass an mot and thus un-road worthy making the car illegal on roads. I also dont am not sure where you would stand even if your decat is declared with insurance due to the fact im sure my insurance policy states that the car has to be road worthy.

I got stopped by the police several times with my decat no worries at all. I also did a lot of research on what would happen with a decat fitted and from what i can see VOSA (they are to do an emmisions test at the side of the road) would just issue you a notice to get your car re-tested at the nearest MOT station.

The light on a decat is an easy fix which you have several options
-Dont re fit the second lambda Just wrap it in a bag and cable tie it somewhere(plenty of post of people on here have done that.)
-Fit one of these if you want to do it properly http://www.k-tecracing.com/show_product.asp?id=4347&appid=2
-Just cover the light in tape/remove it
-Or just live with the light.


The only issue i had with my decat was that it gave my a f**king terrible flat spot at 3-3.5k rpm which resulted in me constantly getting little dildos in ford fiest zetecs being able to pull away from me. not that i recommend this but its another option at MOT time find a friendly mot tested and leave a crate of his fave larger on the passenger seat with a £10 lol

also the decat vhange on a 182 is easy. on a 172 you have to have hands the size of a 2 year olds.

 

[Chip-mk1]

good thing I've got one with man-spec then

Only if you have fitted a V8 recently, or at least supercharged it or something.

 

[Martin.]

Thanks Dom. I've got too many lights on already lol so don't want any more. Service, ABS and Traction control.

Won't a remap get rid of the lights which appear on the dash? And wouldn't it smoothen out the flat spot in the rev range??

I do know one or two friends who do MOTs. I guess that wasn't my real bother. Just having a non road legal car, with potentially void insurance.. Just for the sake of a little bit less back pressure.

 

[Chip-mk1]

If the remap is suitable for a decat it will cure the flatspot.
It wont turn the lights out if there is a reason for them to be on though (ie they will go out after the remap as the ECU will reset but may then come instantly back on so you wont ever see them being out)

 

[BigDaveRotary]

Thanks Dom. I've got too many lights on already lol so don't want any more. Service, ABS and Traction control.

If you are talking about the SERV light. Then that isn't a service light IIRC .Think it is to do with your brake fluid being low? I know mine came on and that was the issue!

Someone correct me if I am wrong!

 

[Martin.]

If you are talking about the SERV light. Then that isn't a service light IIRC .Think it is to do with your brake fluid being low? I know mine came on and that was the issue!

Someone correct me if I am wrong!

Really? Didn't know that. Thought it was something to do with my new seats, but put the resistors in the connections to get rid of the air bag light only...

I only had my fluid flushed and changed recently and it's still showing pretty high so don't think it means fluid too low.

 

[Chip-mk1]

Serv light is multifunction, airbag throws it on iirc on ph2, so probably was your seats causing it.

 

[The Dominator]

I have a sports cat in mine reason being I couldnt actually find my cat when I wanted to put it back in, the decat made my ears bleed on long journeys so got a sports cat

 

[Martin.]

Serv light is multifunction, airbag throws it on iirc on ph2, so probably was your seats causing it.

I had the serv light and air bag light pop up when I changed my seats. But put the resisters in and they disappeared. Now the serv light seems to have popped back up again with the ABS and traction control light. Maybe it's something to do with my brakes. Sensor knocked or loose or something.

I have a sports cat in mine reason being I couldnt actually find my cat when I wanted to put it back in, the decat made my ears bleed on long journeys so got a sports cat

Lol. What exhaust do you have though. A yozza would make my ears bleed anyway from hearing videos. I've got a Milltek, it's much more tame at cruising speed.

 

[Chip-mk1]

ABS puts the serv light on too, like I said its multifunction it just means "take your car to a dealer, there is a fault that needs fixing" which applies to brakes/airbag/engine etc

 

[The Dominator]

I have the ktec/janspeed slash cut system with the sports cat it's ok with normal driving but sounds nice when HOON mode is engaged

 

[dmallett]

Milteks just drone on motorways imo.

Didnt really notice a noise difference on my car when going from sports cat to decat. My ktec sports cat i had passed an MOT no problem.

Just go for a decat and then swap back to your standard cat for MOT time, doesnt take long.

 

[davebem]

Can anyone confirm if a sportscat is illegal? About 5 years ago I hit some bricks in the road, and wrote off my standard twin barrel 172mk1 cat, a new one from Renault was £850. I think I paid £300 for a janspeed sportscat, and it has passed 5 mots since then...My sportscat is bolted to the standard renault exhaust system.

 

[Chip-mk1]

They aren't illegal as such no, so long as they work well enough to meet emissions on an mot