My  car a 2016 Octavia 1.4 DSG , failed it’s MOT yesterday  and I quote : 

• Exhaust hydrocarbon content after 2nd fast idle exceeds default limits (8.2.1.2 (b
  I have left it with the dealer for them to sort, but apparently it may be a PCV pipe at fault which has split , anyone any idea as to what this does , other than split.  Apparently  the pipe itself won’t be  be covered under the guarantee because they’re not , hopefully the rest will be.  

PCV stands for Positive Crankcase Ventilation.

 

It's a system that vents the positive crankcase pressures back into the inlet of the engine. If these gasses are escaping or the engine is sucking in fresh air instead of the crankcase gasses then it can negatively affect emissions.

Genuinely intrigued - how does an engine taking in no oil vapour from the crankcase negatively affect the emmisions?  If anything, surely it helps them?  I know some people replace the pipes with little breather filters so they don't gunk up their air inlet with oil...

Direct emission of the oil mist/vapours into the atmosphere, probably.

It's been illegal for engines to do that for a few decades now.

Edited 15 July, 20205 yr by Wino

 It turns out after 5 days investigation that a faulty lambda sensor was to blame ,instructing the car to over fuel and ruining the catalytic converter. Not to worry said I all along I have a Skoda approved used car warranty, should have ripped it up and sold it as bog roll when there was a shortage for all that was worth ,  turns out catalytic converter not covered ,£1600 shaped hole in my bank account now.  

Ouch.

To be fair, that's why I didn't worry about buying from a dealer when I got my car.   My parents bought from a skoda dealer many moons ago and I still remember them slowly finding out how little was covered and getting increasingly annoyed.

 

Surprised the car doesn't flag up a faulty O2 sensor though.

If the sensor still reports a plausible signal (within a specified range) then it won't trigger a fault unfortunately.

To be fair to the garage , the car didn’t show any faults , so it was back to old school methods ;£1600 still hurts though.  

But surely if it's a faulty sensor that's caused it then it should be covered? Or is the sensor not covered either?

I’m not sure whether the sensor is covered, even if it was the cost of the consequential damage to the Cat is down to me.  Wonder if Skoda might contribute? 

@JamesETheFirst  Is this the cars 2nd MOT? 

It is the Warranty Underwriter of the Warranty with the Skoda Approved Car that has to say what or what is not covered and for them to pay.

Why would it be Skoda that has to contribute, other than in an arrangement between them and the Warranty company that actually will be VW Group owned.

My previous experience of the Skoda approved warranty was that we had a starter motor problem. At first the garage said it's not normally covered under the warranty but they would submit a claim to the warranty underwriter and see if they would accept it anyway, which they did!

 

1 hour ago, Roottoot said:

@JamesETheFirst  Is this the cars 2nd MOT? 

It is the Warranty Underwriter of the Warranty with the Skoda Approved Car that has to say what or what is not covered and for them to pay.

Why would it be Skoda that has to contribute, other than in an arrangement between them and the Warranty company that actually will be VW Group owned.

The car a has been serviced by Skoda, has low mileage , so the part has failed , in my opinion prematurely.  

If you had it from new then your opinion might matter, as it is a Warranty manager needs to get involved.  Get the decision in writing. 

15 minutes ago, JamesETheFirst said:

so the part has failed , in my opinion prematurely.  

 

I agree. I'd add the word very in between the words opinion and prematurely.

 

Whatever happened about the PCV fault, was that confirmed/fixed? Just wondering if that may have been a causative factor in the oxygen sensor failure, if it was making the engine run sootier or oilier, coating the sensor's critical surfaces?

17 minutes ago, Wino said:

 

I agree. I'd add the word very in between the words opinion and prematurely.

 

Whatever happened about the PCV fault, was that confirmed/fixed? Just wondering if that may have been a causative factor in the oxygen sniensor failure, if it was making the engine run sootier or oilier, coating the sensor's critical surfaces?

That is a very good question , one which I will be asking