Hi all,

After collecting my 03 wrx last week I am already looking for some mods to do. The car is totally standard. The std exhaust looks like its on its last leg so will need replacing, which would be an ideal opertunity to replace it with an uprated item.
So, my questions are, i like the look of the standard pipe, but would be nice to have more noise. Ideally this year I want to also have the car mapped, so want the hardware in place for that. I have read that there are 3 cats? then a centre section with a box and finally the rear.
Which cats would I have to leave in so the car would pass an mot?
Can i simply replace the centre box section with a straight throug pipe or will that be too loud?

Any adice greatly appreciated.

Thanks

 

The WRX has a cat in the up pipe, down pipe and centre I think.
Apparently the one in the down pipe is most restrictive.
AFAIK you can replace the centre section and up pipe with decat items, and run with just a 100 cell sports cat down pipe and still pass the MOT (someone correct me if that's wrong).

I'd recommend that if you're having it mapped then you replace the lot in one go - I had mine mapped after just replacing the centre and backbox for Milltek items and still wish I'd done the down pipe and up pipe at the same time.

With a decent map and exhaust, and after-market panel filter (like Green, K&N, TSL etc) you may see around or more than 270bhp with just those mods (although according to some people on here it's best to fit an uprated fuel pump at the same time).

The choice of exhaust will be down to personal taste. A fair few people run the Nur Spec R from Blitz which sounds great (damn loud) but is too loud for everyday use for me (my Milltek gave me a headache when I first had it fitted ). There's also Hayward and Scott, TSL, Milltek, Prodrive and many others. Scoobyworld also do their own Afterburner, Ninja and Racebox exhausts. I had a racebox before my milltek; sound and size was similar to the OEM item but I think you'll regret it if you don't go for a better sounding item.

Let us know what you decide and welcome to the world of modding ; hope your wallet's ready for it

 

my thoughts at the moment were keep an eye out for 2nd hand items, would it be ok to fit a backbox and centre without having a re-map? then later when ready for the map do the down/up pipes?

 

Yip.

Are you from Durham, as you username suggests?

If so, have a look here: www.tyneteesscoobies.co.uk

 

Hi Micky,

yeah, from Durham, cheers for the link! awaiting admin to activate my username.

Cheers

 

dont know if its any use to you but im selling my TSL group N backbox in a few weeks,see here...https://www.scoobynet.com/private-sa...n-backbox.html it looks the part and sounds great without being over the top

 

Hi Chris !

Ran mine with a catted system for a full year till I got mine mapped, may throw a CEL but at least you know it's only a cat out of range error.

HTH

DunxC

p.s. I have a cat free up-pipe off an STI if you want one !