Lately the oooommf seemed to disappear from my STI so I took it to PE for a diagnostic power test - and as I suspected it turned out to be 40 BHP down. After much testing and swapping things in and out, it turned out to be the cat in the downpipe which had broken up and was blocking the downpipe cat and centre cat.

So these were replaced with catless sections, so now I have no cats at all - question is, what happens at MOT time? Will swapping in the blocked centre cat (now buggered) be sufficient for the MOT? Thankfully not for another 11 months.

 

Buggered cat won't help anything! A straight replacement centre (with no downpipe cat) probably wouldn't pass an MOT - it's only designed to 'clear up leftovers' from the downpipe cat.
For MOT purposes, there are places that have a double centre cat (a primary and secondary cat in the centre pipe rather than just a secondary) which will pass. The closest that I know of to you is subaru-4-you who will basically lend you the pipe for the day to get the MOT done.
Or, you can buy the highly expensive sports-cat centre from PE, which stays on permenantly & does the job enough to pass current tests.

 

Whats your car and how did you bugger your cat??

 

Its an STI 2 and I don't know how it happended its just been losing power recently.

Brian

 

nom,

just spoke to PE and they do a similar swapping service. Phew.

Brian

 

A lot of people have replaced to the downpipe for a catless version and left the centre as is (with a cat) and thay've passed there MOT's.

I think you'd get away with just changing the centre evey 12 months