ctommo88

I have a cobra 5" slash cut exhaust which is strait through from the original cat (non resonated) and was thinking of going for a decat as theyre only £55.

Would like some opinions please on doing this e.g. is a remap really necessary? I currently have the prodrive package on my 2003 sti type uk.

jura11

iTrader: (7)

If you are go for full decat which is downpipe,centre pipe and up pipe,you will need remap.But if you are go just for centre pipe and backbox you will be fine without remap.

midnight

iTrader: (10)

What age of car do you have as some of the classics run fine with a full decat and no remap,but newage will definetley require a remap. Sorry mis read your thread 2003 remap required

djandyg

iTrader: (2)

i think he's prob referring to a backbox, centre pipe and 2nd cat delete, but leaving the 1st cat present....

ctommo88

Yes I currently have a cat-back with no resonator and just wanted to get rid of the 2nd cat.

Is a remap required for this?

turboaddict

iTrader: (2)

no you will be ok with running the s.s back box the 2nd de cat center pipe with out a re map as stated above....

djandyg

iTrader: (2)

Forgive me if im getting my wires crossed and mis understanding your post, but I still dont think thats the cat he's referring to mate.... As IIRC the centre pipe isnt a cat its just a silencer...he's already got the straight thru pipe for the centre...
...he means this (the short pipe AFTER the centre pipe)
http://www.cobrasport.com/images/products/356.jpg

I know a lot of companys seem to call the straight through centre section a 'centre de-cat' section for some reason, which is daft because its not actually a cat.

Im unsure on the remap, but i would imagine it might cause your cel light to come on, due to the fact you'll be sticking one of the O2 sensors into the pipe which was previously placed just after a cat.

As far as im aware your car should still pass an MOT emissions test tho due to the first cat immediately after the turbo still being present, but there is the potentially for overboost if you dont have a remap as your turbo spool time will be less.

ctommo88

Yes, that is the pipe im after. So it'll end up just a strait through pipe from the turbo down pipe cat to the muffler.

http://www.scoobypedia.co.uk/uploads..._schematic.gif

Has anyone had any experience in fitting these, is there any sensors going into the cat that I need to reconnect to the decat pipe etc.?

jura11

iTrader: (7)

Hi mate its dead easy to fit centre pipe(30mins its slowest time),i have JDM bugeye WRX which doesn't have any sensor,but use OEM gaskets,don't use paper gasket

ctommo88

OK cheers mate, Did you notice much of a noise and power increase on yours then?

jura11

iTrader: (7)

If you really want increase power,i recommend you de-cat downpipe(Cobra selling for good money or just check eBay or here in For sale section),and up pipe(Harvey here selling and most people recommend or just look on Cobra,eBay etc.),and after this you will need remap(open source is cheapest option for you,350£ or EcuTek 600£)and you will see 40-50bhp increase in power.
If you fit just centre pipe power don't increase,just noise,i'm afraid

djandyg

iTrader: (2)

I would imagine there is a sensor as the decat pipe your looking to buy has a bolt hole welded in place for it

ctommo88

Well a louder exhaust is what i'm mainly after but power gains would be nice, the prodrive does make a hell of a difference.

Thats what I noticed in the picture djandyg, as its only the second cat im not sure the warning light will come on as Cobra claim they pass the MOT's