impreza which catalyst for mot

[Jmk]

hi mot is due on my mark 1 sti it has a 3 inch straight through exhaust the engine was mapped without a exhaust cat will the car run ok / pass the mot with a cat fitted or will i need a remap the car would need a new ecu so a remap wouldnt be cheap which cat would be best sports or normal and as the exhaust is 3 inch would there be an off the shelf cat section or would i need to go custom thank you for your help - jon

[Hol]

Jmk said:

hi mot is due on my mark 1 sti it has a 3 inch straight through exhaust the engine was mapped without a exhaust cat will the car run ok / pass the mot with a cat fitted or will i need a remap the car would need a new ecu so a remap wouldnt be cheap which cat would be best sports or normal and as the exhaust is 3 inch would there be an off the shelf cat section or would i need to go custom thank you for your help - jon

If your mapper was good, then just replacing the centre pipe with a standard classic STI CAT should suffice. They are 2.25in as standard.

I used to use a specialist in Essex who would hire you out and fit a centrepipe that had two standard cats in it. Even with a 400bhp remap it passed a proper MOT at a vauxhall main dealers down the road from them.
The car did feel decidedly suffocated though, until I returned from the MOT and they put the original 3in system back on.

[TAS1981]

If its an imported V1 Sti then you don't need a cat as its not in the Vosa database, you just need to convince / use a tester who knows that.

I know because I had one.

[liner33]

TAS1981 said:

If its an imported V1 Sti then you don't need a cat as its not in the Vosa database, you just need to convince / use a tester who knows that.

I know because I had one.

That might work until next year when anything that had a cat when it left the factory will require one for the mot regardless of emissions

Best advice is find a friendly mot guy

[TAS1981]

Ok, that's interesting... I wonder how they will do that if these cars are not on the VOSA database... I mean I thought that was the reason that they were not tested... if they don't have the information readily available (assuming Google does not become standard practice) then how can they say?

I guess its going to tighten up...since I am not in the UK as of a few weeks ago I was not aware and enjoyed 4 years of no emmissions tests!