Failed MOT........any ideas?

[LiamR]

I have an old ford puma as a little run around and today it failed its MOT on the following:

Exhaust emissions lambda reading after 2nd fast idle outside specified limits

The fast idle test gave the following results;
CO max 0.30% - 0.03%
HC max 200ppm - 9ppm
Lambda 0.95-1.09. - 1.03

All the above are passes. So why has it failed? And what would be causing this?

Any ideas greatly received :)

[Ian S]

The best person to ask would be the man that failed it?

[LiamR]

I did. He was a bit rubbish in his reply. Said it may be the little leak on the system, maybe the cat, maybe the back box........ All a little vague.

Other forums are saying it may help to take the car for a good run before the retest as a warm cat performs better, a bit of tank additive etc. I just thought some knowledgable chap on here may be able to shed more light on the issue.

[Ian S]

What part of emissions did it fail on?

[Brigsy]

Go and flog the nads off it before retest. Many cars wont pass emissions unless the cat is hot, saxo vts's are a nightmare for it

[Sparkie]

i have to do the same with my dti scenic.
give a prolonged thrape until its reaally hot....

[gttjames]

he said it could be the minor leak? Well why not just put some sealent over the minor leak and get car upto temp when you take it for re test.

Or leave a 10er on the seat:confused:

[LeeR5GTT]

its likely to be the minor exhaust blow mate. Happens to me alot while testing cars :)

[Nick k]

Does it idle ok? i asked this because i know that they have updated the limits and brought them really tight. If the manufacturers say its idles at 850rpm it will fail if its idling above that?! :crap: Them reading you have put look ok...

[LiamR]

Thanks for all the replies. Much appreciated :agree:

I bought a new back box for the car but haven't fitted it yet.

In relation to the MOT, I was still confused that the emissions paperwork said 'pass' but it had failed. I returned to the MOT station and showed the tester. He was confused, apologised profusely and issued me with an MOT certificate :)

He apologised loads- so I said he can make it up to me when he eventually MOTs the 5! :laugh:

[gttjames]

Thanks for all the replies. Much appreciated :agree:

I bought a new back box for the car but haven't fitted it yet.

In relation to the MOT, I was still confused that the emissions paperwork said 'pass' but it had failed. I returned to the MOT station and showed the tester. He was confused, apologised profusely and issued me with an MOT certificate :)

He apologised loads- so I said he can make it up to me when he eventually MOTs the 5! :laugh:

haha good work

[Mr Raider]

Or leave a 10er on the seat:confused:[/quote]

Lol that sounds familiar! :laugh:

[gttjames]

;)

[Tony Walker]

with those results its a pass. You need to show us the 2nd fast idle results

[Tony Walker]

Its a very good pass too.