Exhaust choices

[kineticz]

Good afternoon,
I am planning to fit a new exhaust and decat in early January. Now I have a couple of questions. Firstly, the exhaust. I have always liked the twin exit design at the rear such as this:

http://cgi.ebay.co.uk/DUPLEX-TWIN-E...14&_trkparms=72:1301|66:2|65:12|39:1|240:1318

What do you guys reckon to that?

Secondly, I've found decats such as this which say they have the sensor holes:

http://cgi.ebay.co.uk/VW-GOLF-GTi-S...14&_trkparms=72:1301|66:2|65:12|39:1|240:1318

But even with the sensors in, will the ECU still flag up an error?


Many thanks for your response.

 

[LEE69]

Exhaust isn't my choice as you'd need another hole cut out.

The second lambda (after the what would be the cat) will be getting the wrong reading so will flag up the EML

 

[MrJohnnyB]

You drive a 1.8T 20v turbo why, oh why would you decat it? Be such a PITA come MOT time. I agree i do like the twin exhaust look but tbh is it really necessary?

 

[kineticz]

Why would I decat it? Like alot of other people do - for faster turbo spool up times and will help when I come to get a stage 2 remap. Would the EML cause the car to run with restricted parameters to protect itself? I would get a sports cat but they are so expensive

Is it necessary? In what way do you mean? It's a question of taste and preference. I like the look and I want the sound. I haven't seen any other Leons with twin exits like that before so that unique-ness also appeals to me. Cutting another gap in the bumper isn't a problem.

 

[MrJohnnyB]

Diesels can be decatted because they dont have to pass emissions tests, if you take the cat off your petrol car it will be flagged up on a MOT and fail... hence why people who own petrol cars go down the route of sports cats.

 

[LEE69]

Diesels can be decatted because they dont have to pass emissions tests, if you take the cat off your petrol car it will be flagged up on a MOT and fail...

You put the CAT back on for MOT time

 

[kineticz]

I know that mate, but are you saying the added performance benefit of decatting is not worth the hassle of having to changeover come MOT time?

 

[MrJohnnyB]

I personally would say no its not, because it also makes the car illegal on the road, which if it comes to making a claim or u write the car off or anything you will get raped in the arse... all for £350...

 

[LEE69]

Of course it is you'll get about 10 bhp i'd have thought, but you'll get the EML light on.

 

[MrJohnnyB]

Each to their own i guess I spose with the new proposals to increase the duration of MOT's from one year to two will encourage this kind of thing more and more

 

[kineticz]

Now are you saying that being raped in the arse is not worth the decat?

haha jokes...

Do you think I should just get it remapped stage 1 then and leave it at that?

 

[kineticz]

Of course it is you'll get about 10 bhp i'd have thought, but you'll get the EML light on.

Will the EML cause the car to run in 'restricted mode' like it did when I had the ABS ring fault, or not?

 

[LEE69]

it will, but you can get that mapped out.

 

[MrJohnnyB]

Should imagine so, but anyway when you get it remapped they can just map the 2nd sensor out i believe... what he said

 

[kineticz]

OK, so if I got the decat and the back box system, but left the 'centre section' OEM i.e. pipe from cat to back box, would that be OK for a stage 2?

 

[MrJohnnyB]

the downpipe is probably a similar size to the decat and the rest of the exhaust. The cat is the most restrictive thing. But different mappers require different modificaitons for stage 2...

 

[kineticz]

the downpipe is probably a similar size to the decat and the rest of the exhaust. The cat is the most restrictive thing. But different mappers require different modificaitons for stage 2...

I have heard that for stage 2 I need:

Forge valve
induction kit
Decat
TIP
FMIC optional but recommended

 

[MrJohnnyB]

I think u need to uprate your FPR too...

 

[kineticz]

I'll look into that.

Will a decat, and the twin exit back system work OK together then fitment wise?

 

[MrJohnnyB]

Depends on how well they mate up, i know that a lot of products are not compatible straight out of the box, but no reason why you couldnt modify them to fit really...