I've had a search in my tapatalk app for info on decat an vrs but I cannot find anything :-( just irrelevant threads

What I really would like to know is

1) is it worth decaying the car and what gains are to be had

2) would it need to be mapped in

3) is it as simple as just cutting out the car or buying a decat ?? And do I need to worry about any sensors goin ape or gaskets ??

Any help very much apreciated

1) There are no gains to be had, this is a turbodiesel car and it doesn't work the same as petrol engined cars.

 

2) No need to remap since there are no gains to be had.

 

3) It isn't simple since the missing cat will be an automatic MOT failure, there has been much wrangling about putting a fake cat in to fool the MOT man, but since there are no gains or advantages to be had it seems like an awful lot of trouble for no reason.

Very slight power can be made

No mapping needed for it but will be better if you do to help in turbo spooling

If u buy a decat down pipe then the mot has to price that there should be one from the factory. Which is almost impossible lol

If u buy a decat it will put the engine warning light on the dash a map can clear that also should come with gaskets and that. Im going to go for a 2.5inch piper decat then cat back. For noise and better flow from the engine out. It will smoke more aswell i guess. But o well

Why does the eml come on? And I was just asking about the mot as I had as stage 2 306hdi with decat and went through mot with no issues for 4 years just this is a lot newer didnt know if it would be an issue :-/ so really its a pretty pointless mod ? Should just stick with a cat back ? Or is turbo back another option ? As that's what I had in my 306 and made it rev freely a lot more :-) not very clued up with these modern engines :-( I it helps I'm looking for around 210/20 bhp or so just looking at what to do first

Edited 28 August, 201411 yr by jukie88

Decat will make the car better. I don't know what people are taking about when they say no difference at all, it will not throw the eml on the dash another lie

Buy a proper decat pipe then no one will know if it had a cat or not. If u just cut the old one out and weld in a bit of pipe it will fail mot. As it's ment to have a cat for the mot if it's missing it should fail

As above it will make a difference, just not a lot on a standard set up.

Even changing the restrictive supposedly performance Miltek back box on mine made quite a difference, it was running 32psi of boost.

Had a smaller back box system made up by Longlife and it boosted to 35psi, same downpipe/system diameter too so it was deffo backbox restricting it.

If u buy a decat down pipe then the mot has to price that there should be one from the factory. Which is almost impossible lol

Not really, a quick call to a dealer with your vin number would be all the tester would need.

pretty sure if you tried telling them how to do there job and what should and shouldn't fail they would soon pick up the phone!

Wow I think u need to find a new tester. During an mot your not ment to leave the bay the car is in being a tester. So going to the phone to phone a dealer is a no no according to vosa! If you don't know if it's ment to have one or not you have to pass and advise!

Waits for you to argue back

Edited 28 August, 201411 yr by k666sdb

Decat will make the car better. I don't know what people are taking about when they say no difference at all, it will not throw the eml on the dash another lie

Buy a proper decat pipe then no one will know if it had a cat or not. If u just cut the old one out and weld in a bit of pipe it will fail mot. As it's ment to have a cat for the mot if it's missing it should fail

I thought all decats would bring a engine warning light on for emissions from the lamber sensor ? Could be wrong but everyone I have spoke to with decats all have/had a warning light come up.

This is a diesel mate there is no sensors in the exhaust on our vrs

Wow I think u need to find a new tester. During an mot your not ment to leave the bay the car is in being a tester. So going to the phone to phone a dealer is a no no according to vosa! If you don't know if it's ment to have one or not you have to pass and advise!

Waits for you to argue back

Pop a link up please to that info from VOSA

Or was it a m8 down on Mcds car park told you that?

The only part I can spot in the VOSA guidelines says about them not being interrupted during the test, no mention of not leaving the car.

No the vosa bloke told me that while I was having my training for my licence,

So no my mate did not tell me that in a car park.

Iv just thought iv seen your signature on the 306 forum saying supercharged slayer or some ******s like that. Your just a full blow key board warrior ain't ya? Ha.

But back to the actually subject I would say yes to a decat if your looking for power. If you are not then just keep it.

No the vosa bloke told me that while I was having my training for my licence,

So no my mate did not tell me that in a car park.

Iv just thought iv seen your signature on the 306 forum saying supercharged slayer or some ******s like that. Your just a full blow key board warrior ain't ya? Ha.

 

VOSA bloke told you,ok.....

Ok so after reading I've decided coskev is of no use to this thread plz remove yourself,

So decat is ok mot will be fine as I've been down to my garage and they say its fine as long as it passes the smoke density test, so after using good old google few ppl have said that it throws a eml :-/ but I don't see why if there's no sensor the back box will be removed and replaced with either a piece of pipe or a performance cat back system :-) then remap I think any ideas on a good reasonably priced exhaust system

Edited 28 August, 201411 yr by jukie88

Exhaust mods only worth doing once you're on the 220bhp threshold, this 'quicker spool up' is just pub talk, it's a VNT the 'spool' is controlled by the ECU.

 

Don't waste your time, plenty of people on here with very quick cars and standard exhaust systems will tell you exactly what I've told you.

The only gain that you can quantify (IMO) is the sound you get

Anything else is too subjective/minimal to worry about in my eyes.

VOSA bloke told you,ok.....

you just a turd, yes the bloke who's comes around and checks me once a year, i know you might think you know stuff about this but you actually don't, you just read stuff and think you know the lot.

 

jukie88 get a decat as jars said you get a nice turbo noise too from it as well and it won't bring any light on your dash i can guarantee that

Edited 28 August, 201411 yr by k666sdb

So what gubbins do I need to achieve the 210/20bhp mark ? Surely ill need a free flowing system ?? It can't just map to 200 surely :-/

Edited 28 August, 201411 yr by jukie88

So what gubbins do I need to achieve the 210/20bhp mark ? Surely ill need a free flowing system ?? It can't just map to 200 surely :-/

 

No, it can only map to 175bhp unless you fit a different turbo, hence my advice.

I'm running 186hp and 300lbft on standard turbo, but with decat and airtec intercooler and a map

So map to 175 how am I getting the other 40bhp ? :-/ sorry or the silly questions but trying to search for info on this forum just keeps sending me to dead end threads :-(

you will require a bigger front mount intercooler and a hybrid turbo with the exhaust system 

where re you located jukie88

Edited 28 August, 201411 yr by k666sdb

I'm still a bit miffed on the whole cat situation on these cars. Is it merely to reduce hydrocarbons and not soot? I'd have thought this must be the case with us not having a DPF.

So regardless of whether the car had a cat fitted from the factory, so long as it passes a smoke density test everything is ok? Just to add, why are people failing MOT's for having a mufflerectomy?

(sorry if this is viewed as O.T I thought this was a good thread to bring it up in).

sent from my Galaxy Note 3

No, the cat is there to reduce NOx emissions, it's not a DPF, NOx is what causes that brown haze you see above cities on hot days, particulates are what makes your snot dark grey when you spend a day out in a city.