MOT emissions

[dav123a]

Just got my 1.6 focus back from MOT and one of the emmission results was close to the limit.The natural idle test CO was 0.283.What might cause this to be so high ?

[The Wookie]

Knackered Cat or Lambda sensor would be my best bet.

[Scuffers]

dav123a said:

Just got my 1.6 focus back from MOT and one of the emmission results was close to the limit.The natural idle test CO was 0.283.What might cause this to be so high ?

can you post the full set of figures up?

specifically:

HC
CO
Lambda

at both idle and fast idle

[dav123a]

Hre they are

Fast idle
CO 0.003
HC 21
Lambda 1.006

Natural idle
CO 0.283

[Scuffers]

dav123a said:

Hre they are

Fast idle
CO 0.003
HC 21
Lambda 1.006

Natural idle
CO 0.283

no HC and lambda for Natural idle?

that asides, Fast idle figures look spot on.

[dav123a]

No they were not tested . Fast idle seems fine it was co at natural idle that had me thinking. Was pretty close to limit and alot higher than a couple of years ago .

[Jimmyarm]

Hi CO is usually a hole in the system somewhere from my experience.

[Dr Doofenshmirtz]

Jimmyarm said:

Hi CO is usually a hole in the system somewhere from my experience.

No, that's lambda.

The readings are fine - the cat converter was probably just a bit cold. They need to get properly hot to get a really low reading.

[dav123a]

Was under the focus a couple of weeks ago and didn't see anything but I will take a look. Would that give such a difference in co levels between idle and fast idle ?

[Scuffers]

dav123a said:

Was under the focus a couple of weeks ago and didn't see anything but I will take a look. Would that give such a difference in co levels between idle and fast idle ?

Dr Doofenshmirtz said:

Jimmyarm said:

Hi CO is usually a hole in the system somewhere from my experience.

No, that's lambda.

The readings are fine - the cat converter was probably just a bit cold. They need to get properly hot to get a really low reading.

what he said.

noting wrong with it.

[Mars]

Dr Doofenshmirtz said:

the cat converter was probably just a bit cold. They need to get properly hot to get a really low reading.

Yes, to get the Cerbera through I used to have to give it a proper high revs blast to get the cat almost glowing. But the difference between cold and "glowing" was incredible. It'd start with readings above 6000 and still it'd get through eventually (just).