MOT Fail - emissions

[Elfy]

Just a quick question, my clio 182 had its MOT today and failed on this one thing.

It says "Exhaust emissions lamda reading after 2nd fast idle outside pecified limits"

Is this more liekly to be the pre cat lamda thats at fault and needs replacing?

Sorry if it has been asked before.

Alex

 

[v16daf]

Is it de-cated?

 

[Elfy]

Nope not been de-catted so i assume its that lambda and not the post lamda?

I have had the engine management flick up a few times for a few days then go off again within the last few months

 

[v16daf]

Nope not been de-catted so i assume its that lambda and not the post lamda?

I have had the engine management flick up a few times for a few days then go off again within the last few months

I'd double check with Fred etc, I know my car failed on this when I tried it with a de-cat fitted, so I reckon it's the lambda?

 

[clioruss]

usual rectification to that. tell MOT garage you want em to re gas test in half hour.
go and run it RED HOT.
I have had similar issues when like that and the suggestions were sent to me wen asked and all was ok.

 

[Elfy]

I'm thinking lamda also

Car was red hot before test, had a half hour drive to test centre (as MOT is at mates rates) they did try it twice. He said he checked the exhaust wasn't blowing and all vacuum pipes were ok so could only assume its the lamda at fault.