HELP!! I have a 2012 Fabia and I have had repeated M.O.T. test failures due to emissions. I have replaced  both Lambda sensors filters and everything I can think of apart from  the CAT. The emissions fault light is not lighting up so apart from replacing the CAT I am at a loss what to do next, I would appreciate a little help please.

What petrol engine is it? There are quite a few different ones.

https://en.wikipedia.org/wiki/Škoda_Fabia#Engines_2

 

Which numbers in the emissions test are causing the problem, CO, lambda or HCs, or more than one of those? Can you post a photo of the emissions test sheet?

 

Does the emissions light show briefly when you turn on the ignition, before starting the engine? (A previous owner may have obscured it to cover up a fault).

Hi there thank you for your speedy reply

 

The emission light appears to be OK, see below content as set out on the MOT certificate 

Exhaust carbon monoxide content after 2nd fast idol exceeds default limits [8.2.1.2 (C) 1

Exhaust Lambda reading after 2nd fast idle outside specified limits {1.1.12 (b) (ii) }

Have you checked the brake servo vacuum line for cracks and leaks? They tend to go either side of the non-return valve near the throttle body.

 

@bazzerfewi   Welcome. 

What engine does your car have?

Hi Wino the servo pipe appears to be ok, what do you think in regard to 

 

Exhaust carbon monoxide content after 2nd fast idol exceeds default limits [8.2.1.2 (C) 1

Exhaust Lambda reading after 2nd fast idle outside specified limits {1.1.12 (b) (ii) }

 

will the servo pipe effect this

 

•  
• Quote

Yes, that's why I suggested checking it. Any uncontrolled air leak can make the engine run beyond its calibrations. 

 

Does the engine warm up fully, needle to middle of coolant temperature gauge?

 

Really need to know what the numbers were from the emissions printout, i.e. how close to the limits was it. Might just need a brisk drive in lower gear to burn some soot out of the cat(s).

 

Also need engine type so we know what we're dealing with.

40 minutes ago, e-Roottoot said:

@bazzerfewi   Welcome. 

What engine does your car have?

It has a 1.2 three potter

skoda fabia 2002 3 cylinder

Ah, so the 2012 was a typo. It's a mk1. How many miles has it done? Does it do mostly short runs?

Any misfiring at idle when warmed up? 

There's another pipe you could check for air leaks, I'll dig out a picture.

Edited 26 November, 20205 yr by Wino

Not sure yours will look exactly like this, but there will be something functionally similar.  Look on the left end of the engine for the PCV valve and check the ends of that loop I've labelled output hose, especially the rubber coupling bits, they can perish and leak badly.

 

 

1.2 6V with leaking exhaust valves?