Exhaust emissions

[karlj]

I'm thinking of running a 4-2-1 straight though system but I know it won't pass the mot emissions test, would adding a performance cat between the manifold and the rest of the system help to get it to pass?

The cat would end up close to where the second cat is.

 

[karlj]

this is the type of cat i'm looking at or this

 

[skymera]

Reach down, realise your testicles are still there then slip the mot tester a Tenner

Performances cats will pass an emissions test so you're cool buying it

Sent from my GT-I9100 using Forum Runner

 

[will930]

fyi my car passed mot with rear the 2nd cat before

 

[karlj]

fyi my car passed mot with rear the 2nd cat before

Cheers Will, looking at options for what we spoke about

 

[Jay101]

fyi my car passed mot with rear the 2nd cat before

How close was it to the fail mark will?

 

[frank]

and what does your post say will ? (in queens english)

 

[skymera]

and what does your post say will ? (in queens english)

He meant to say he passed his mot with the rear 2nd cat only.

Must have been very close to fail? A pass is a pass

Sent from my GT-I9100 using Forum Runner

 

[frank]

plenty of us have passed "without" the 2nd cat, i dont recall anyone passing with "only" the 2nd cat tho

 

[karlj]

But what I'm asking is would I pass with the setup described it the op?

 

[frank]

But what I'm asking is would I pass with the setup described it the op?

nobody has actually tried it have they karl ? (so we would just be guessing)
paul (polly) had problems getting his sports cat to pass iirc

 

[karlj]

Wasnt that on the turbo setup though? Suppose the only way to find out is to just do it and if it fails return to stock for the mot

 

[frank]

Wasnt that on the turbo setup though? Suppose the only way to find out is to just do it and if it fails return to stock for the mot

sounds like an expensive/pointless exercise to me mate (unless you,re anticipating a roadside check ? )

 

[karlj]

Not really that expensive people have spent more on pointless stuff before now

 

[frank]

Not really that expensive people have spent more on pointless stuff before now

amen to that

 

[Low Rider]

Been passing emissions with a 2nd cat for years but it probably falls under the expensive/pointless category considering it's no ghetto setup

 

[karlj]

What's your setup LR? I'm not fussed by cost just looking at options for the moment

 

[Low Rider]

What's your setup LR? I'm not fussed by cost just looking at options for the moment

The last setup was Jenvey ITB's, Omex 600, 264 cams, 4-2-1 manifold and system with a 200cpi race cat and no closed loop lambda feedback, (that's history now). We passed fine before on a Nistune, same cams and exhaust with a stock inlet manifold and GA16DE injectors which was closed loop. We did scrape a few passes on a stock ecu, stock cams, 4-2-1 and stock injectors but it was always a pain and required fiddling with a fuel reg, plenty of trial and error and a friendly MOT guy.

We were always comfortable but close if the car was allowed to warm down much with the OEM cat. As soon as we switched to a 200cpi race cat emissions almost dropped to zero on the same tune. Never tried it with a stock ecu though, those days of ghetto stuff are long gone now.

 

[karlj]

so I'd be best off with a 200cpi cat rather than a 100cpi, maybe worth waiting until I can afford Nistune as well

 

[will930]

i meant i passsed fine just with second cat and it cant have been very warm....

but i dont know if they even checked it tbh