My mot is due in a month so trying to sort things out in advance.

My car is an 2003 jdm sti. At the moment the car has a full stainless exhaust from turbo back so i have no cats.

I have the standard sti exhaust which the old owner gave me but i do not have the downpipe which i believe has a cat?

I had a look down the exhaust system and the end which bolts to the downpipe looks to have a cat in it (i think).

If i bought a stainless downpipe (decat) and fitted this to the original exhaust would 1 cat pass the emissions test or do i need an original downpipe?

The other question I have is my car is a twin scroll so does a uk downpipe fit or do i need a jdm downpipe?

I dont want to go down the dodgy mot route incase I decide to sell the car and have no issues swapping the exhaust over myself for the mot and then back afterwards.

If anyone has a cat or decat downpipe which is suitable drop me a pm as im looking to buy one

 

personally it is alot less hassle to have a friendly mot person, as long as they do the rest of the MOT properly and check everything else but then accidentally put the emission prongs on another car instead of yours when it comes to it then all should be well

 

i have a blob, and have been told that if you have first cat in down pipe, but no cat in the next section (before the centre section) it will pass the MOT. however, if you do not have a cat in the down pipe, but have a cat in the next section, it will FAIL MOT.

For example, from factory, my WR1 only has one cat (sports cat) in the downpipe, and no second cat. this passes fine.

basically, you NEED the cat in the downpipe