Road Legal Decat

[S22 JGS]

Im looking into it at the moment, but im told a company up Brands Hatch way have just developed a new decat pipe which will pass emissions tests.

It works by having a valve which only full opens once you are past 3k revs, meaning that when the MOT people test your cars emmissions, it doesnt open fully and passes the test!!!

Shall be looking around today when i get a chance!

 

[Neil G]

Sounds good

Be interestig to hear wether it actually works though.

 

[Mike_182]

If this is what I think it is, it's not a particularly new idea - you have a straight through system and out of the side of said valve you plumb a CAT in, and then when you get to 3krpm the valve switches and bypasses the CAT.

Please correct me if I'm wrong, but they've been using a similar valve tuning the 1.8T VAG lump for a while.

 

[LRTom]

It's also a system used by Aston Martin and Jaguar to bypass their silencers so that cruising round town is quiet but when you put your foot down and hit a certain RPM the valve opens and you get a straight through system making it alot sportier

Tom

 

[AmirClio]

Decats are not illeagal to start with. My car past its emissions test with it on! It is a legal requirement for them pass the emissions test, but wethere it has a cat or not is not relevant.

 

[S22 JGS]

whether its new or not, it can only be a good thing.
best of both worlds, and i if i can get one for the clio, i will

 

[riz]

s22 let me know if it works out as i want one

 

[S22 JGS]

will do

 

[Si172cup]

Whats the name of the company S22?
Is there a web page?

I'm also well keen on this idea.

 

[Ali]

decat's fine...Mine nearly past Always good when you've got someone on the inside!

 

[Christopher]

^^same here. :approve:

 

[Ollie82.]

Interrrrestiiiing!!

Let me know how your investigation go young Steve...i reckon there could be potential for a group buy at this rate.

 

[davejm123]

yea looks good, best of both worlds

 

[Si172cup]

Guys,

I think the below will help those of you who want to read up on this prior to S22's findings!

http://www.dynoflow.co.uk/dynoflow_erv.html

Looks like a lot of hastle for the end result?:S

 

[Si172cup]

bump.

 

[rory182]

from 1991 onwards a cat was a legal requirement.

If you pass the emissions without one it's due to more modern car engine design if anything and not very likely imo.

 

[Rob_]

Some people are getting a bit mixed up

All cars after 1993 MUST have a cat fitted.

Whether it passes without one is irrelevant if it hasnt got one fitted then its illegal and an mot failure.

However, a lot of garages wont even look

 

[7MAT]

Some people are getting a bit mixed up

All cars after 1993 MUST have a cat fitted.

Whether it passes without one is irrelevant if it hasnt got one fitted then its illegal and an mot failure.

However, a lot of garages wont even look

Its only legal requirement for car manufacturers to build and sell cars with cats fitted. It is not a legal requirement for the owner of the car to have a cat fitted. It is also not part of an MOT process to visually check if a cat is fitted or not - it just has to pass the emission test. Some cars with de-cats can still pass.

If you don't believe me check out the MOT website.

 

[Plodwyn]

7MAT is correct, and another point, when they test your car they have a fast idle test and a natural idle test and both are tested at a particular rev limits. To do this they usually pick up a signal from a HT lead and if a cat is missing then the emissions will be too high in these rev limits and fails BUT if the operator cant attach the sensor to the HT lead then the operator can rev the nuts off the car and this can get the emissions down! The wording is that the operator is not allowed to remove or dismantle engine covers etc so if he cant see a HT lead to attach the sensor he has to do a basic emission test and can rev it as much as needed to bring emissions down, cat or no cat! so if your HT leads are exposed tuf i suppose

 

[donsrno1]

Both posts above me are correct. It is not illegal to have a decat fitted to your car as long as it passes it's emissions test. It is simply that manufaturers have to fit them from the factory by law, but if you remove it 5 mins after leaving the dealership and it passes it's emissions it is perfectly legal.