Sti Prodrive Exhause
 

Does the 2006 WRX STi with PPP have a resonator fitted in the exhaust and if removed how much louder would it make the car?

Believe it does. Just get under the car and take a pic. Will add abit of noise.

https://cimg4.ibsrv.net/gimg/www.sco...14e6e7d0ba.jpg
PPP
This is a PPP Exhaust as fitted to a MY06 STI 9 with the (PPP) Prodrive Performance Pack (I believe )

It does have a resonator fitted, i removed mine from my old 2006 STI it makes it a little louder but not massively.
The pic above has a non resonated pipe fitted and is not part of the PPP.

Yep your right...thats not a prodrive back box either.

As stated above it's not part of the PPPpackage so is standard OEM
http://imdomino.imgroup.co.uk/imggb/...0STi%20PPP.pdf

https://01.img.avito.st/640x480/2959592201.jpg
https://17.img.avito.st/640x480/2959592217.jpg
https://90.img.avito.st/640x480/2959592190.jpg

Yea none of that is a Prodrive system. To improve sound and performance remove middle section as shown by Don. And replace 2nd cat on downpipe with decat. Will still pass mot.

I've gone for a decat down pipe from Hayward and Scott for my foz STi. The rest of the exhaust is standard. Do you think it'll pass or fail the mot? Curious to know

Full decat down pipe? 100% fail if so. You need the cat in the down pipe but can remove second cat.

FSTI has a classic exhaust layout (3 piece) with what might be a cat in the mid pipe as well as an expansion box.
https://www.subaruforester.org/vbull...xt-exhaust.jpg

Possibility of getting away with it the Don, what do you reckon? I've opted for it with the mindset it'll fail just curious and wishful that it'll still pass due to the centre cat and standard back box

If you just have the centre cat then it won't pass. The main cat is in the downpipe. Remove the centre cat and get one in the down pipe. Like sports cat.