Pre cat delete

[JR607]

Hi, this is my first post.
I have just bought a 2008 Viper Green tsi 2.0 on 107,000 in very good condition inside and out (apart from some age related scuffs)
I'm coming form a Golf gti mk5 tfsi which was unloved when I bought it so I did all the usual maintenance bits and it went much better. Then I did a precat delete on it and over a period of a couple of weeks it felt even quicker.
I took it for a stage one remap and the guys doing it were surprised it made 220hp before the map! It then made 253hp.
Now my question is would my tsi engine benefit from a precat delete before I get it mapped?
Having said that the Scirocco is nearly as quick as the Golf so may have been mapped before.

[bigkris06]

So without meaning to spout rules etc decat is illegal on road cars in the uk and will fail your MOT, you could go for a high flow sports cat then you won’t have any issues come MOT time and it will give similar results.
Pop your reg in a reputable mapping com and see what they can do, you may find you can get figures that you are happy with on the stock exhaust.
If you look at the link below the guy had a 2016 with a few mods and got from memory around the 260 mark.
Obviously some people will squeeze every single pony out of a car but that doesn’t mean the car is physically able to do so, so make sure you use a reputable company to do it rather than so guy with a laptop in a car park
viewtopic.php?t=29304

[JR607]

You missed the point.
I'm talking about the PRE cat which is for start up emissions and is separate from the catalytic converter which I don't plan on touching as I do know the rules.
The pre cat is just below the turbo and can be knocked out with a chisel or something then hoovered up, obviously without dropping any into the main cat.
It made a noticeable difference on my Golf and isn't illegal in this country.
I just want to know if how people have got on doing it with this engine as it's slightly different to the tfsi I believe.
I'm no stranger to getting cars mapped, I've had two Fiat Coupe 20 vt done and the Golf so I want to present it to the guys doing the map in prime condition for mapping.
Thanks for the link it's appreciated.

[Cuprabob]

Are you referring to the Secondary Air Injection (SAI) pump that under certain conditions pumps air into the exhaust for a short period of time on start up to get the catalyst up to optimal temperature quicker and reduce emissions?

[JR607]

I don't think so.
This is confusing as it seems to be well known on the mk5 gti forum and I've had one removed before.

[Cuprabob]

Apologies it's not something I've come across, although my MK5 was an R32. Remember the Scirocco uses an early EA888 variant whereas the MK5 GTI uses the EA113.

To be honest this forum is very quiet.

ETA.
OK, I've just had a look on the MK5 forum and I see what you are referring to now. I honestly don't know if the Scirocco has one in the downpipe.

[JR607]

OK thanks.

[bigkris06]

Sorry yes I understand what you mean now, my sons 55 plate did indeed have a two cats, I genuinely don’t know which did what but he swapped them out for a miltek 200 cell sports cat (as it’s currently being built to race production GTI)
I looked on eBay for used cats from a 2.0 scirocco (which had the CULA engine) and it also looks to have the same layout as the Golf GTI. I’m not sure if the cats do the same job though,
Personally, the cats from the GTI scrapped for over £400 (this was a couple of years ago) and that would put a good amount to a sports cat if that’s something you’d consider
Hope this helps

[JR607]

Thanks for the info, the plot thickens!