MOT emissions - understanding failure?

[Toaster Pilot]

Does anyone know of a guide or resource with regards to the emissions test that could help diagnose failures?

Can find lots of specific examples of people asking questions on forums and posting their results, getting a "high HC suggests this so try this" type response.

[BritishRacinGrin]

How many car problems can you accurately diagnose based on a single symptom and no further investigation?

I could probably rattle off 10 potential causes, but it could just as easily turn out to be one of scores of other possabilities that I might not have thought of.

Give us some clues! What make / model of car is it, how many miles, what kind of use / servicing has it had lately, any odd noises, does it smell rich, does it burn oil, what did the COs measure last year, what engine temperature was the test performed at etc etc.

[Toaster Pilot]

I meant in general, I don't have the details of the car I'm going to be diagnosing yet

Surely there's a process of elimination to follow when diagnosing these kind of faults?

[andyiley]

There is, but it is a VERY long list & potentially VERY expensive & where do you start & finish.

These can be as simple, quick & cheap as a loose hose clip on inlet tubing, or as difficult, slow & expensive as a new engine & EVERYTHING in between.

[shoehorn]

The only worthwhile guide to diagnosing such a variable fault that`s not`staring you in the face`is experience.

[PaulKemp]

I hope this will be more helpful than the negative reply's you heve received so far

http://www.crypton.co.za/Tto%20know/Emissions/lamb...

[shoehorn]

PaulKemp said:

I hope this will be more helpful than the negative reply's you heve received so far

http://www.crypton.co.za/Tto%20know/Emissions/lamb...

what is negative about the previous posts?
From the op`s post is seems he has little or no experience,the previous poster was outlining the fact that the op would be facing a potential mine-field.
Especially with out experience or access to equipment to measure or verify any changes you make.

That webpage is meaningless if he has no way of relating that to the actual physical fault on the car,listing air leak as a cause is hardly concise.


I,in the light of the fact that he seems to have no measuring equipment and little or no experience and the hands on approach will advance you faster than any web page was urging him to actually hence forth and get stuck in.
Hardly negative.