Hiya everyone,

I’ve been planning on removing some of the cats on my WRX Blobeye and getting it tuned, as I’m sure many of you have too. I’ve got an STI uppipe (no cat) as I’ve heard about the old cats being sucked into the turbine etc.

I intending to remove the centre section cat and replace the downpipe one with a sports cat. Reading up on it it looks like passing MoT is a bit hit and miss with just a sports cat… what do you guys think? I was considering leaving just the OEM downpipe cat in place or maybe having two sports cats (downpipe and centre section) - or is that a stupid idea? I’m thinking from a ‘liberate more power’ standpoint but I don’t want to fail MoT and then spend more money on mods I could’ve done to begin with…

Thanks in advance,
DAS

 

Prodrive removed the 2nd downpipe cat for their PPP package (rear item 2 below)



and replaced it with a straight through section with brackets onto which you could refit the cat heatshields back around the lambda as per OEM.


For STI models they also replace the down pipe cat with a sports cat

 

Can never understand this dilemma numerous Subaru's about me not one cat to be seen. Now apart from the visual check they all pass with flying colours with a decent map. If they pass they don't generally look for the cat visually and there all tested in government run test stations in N.I.

 

ah I didn’t know they replaced the last cat with a sports one - thought it was just the regular one - thanks for that info. You don’t happen to know what CPI the STI one is by any chance?

 

yeah I’ve heard of some passing with flying colours and then some that fail dismally. So do you reckon that, say with only a sports cat in the downpipe and no others, if the car has a good map it’ll pass MoT test no problem?

 

Why not get rid of them all and buy a sports cat?

 

yeah that was the original idea but I want to be sure to pass MoT tests. I don’t want to fork out more money to buy different cats I should’ve bought in the first place and I also don’t wanna swap the oem cats back on once a year

 

If You are getting it tuned go for sportscat,sell oem ,prodrive sportscat is 100cell but used one will be 16y old -could fail when tested.

 

gotcha. Thanks for the info

 

200 cell sports cats pass no problem.

 

Yes it will, i have a 100 cell sports cat. It passes mot but you need to rev it up loads to get the cat roasting hot. So i'd go for the 200 cell like has been mentioned.

 

Incorrect the Prodrive Sports cat is 200 cell.