Catalytic converter failed after 18 months?

jimmylad007

Hi all.

I took the father in law's car for its MOT today and it failed the emissions test on CO so therefore failed the MOT.

The lovely(ish) receptionist lady told me straight away that I'll need to pay them over £100 to have a new catalytic converter fitted to get it through.

Now the cat that it has is only around 18 months old and has had less than 10k miles worth of use. Surely it can't have had it, can it?

The car is a 2000 Citroen Saxo 1.1L petrol. Mileage is very low for it's age at just over 80k.

Emissions Test Readings are as follows:

Fast idle:
CO 0.62 % - FAIL
HC 105 ppm - PASS
Lambda 0.998 - PASS

Second fast idle:
CO 0.41 % - FAIL
HC 32 ppm - PASS
Lambda 0.994 - PASS

Natural idle:
CO 0.07 % - PASS

The MOT refusal document states:
Exhaust emissions hydrocarbon content after 2nd fast idle excessive (7.3.D.3)
Note that stated HC values are passes so presumably this has been entered incorrectly instead of CO.

The garage is only a one minute drive away, so the engine temperature when I took it in would not have been very high, if that makes any difference.

I just wondered what your thoughts are on the matter. OK it's an old car so it doesn't come as a surprise that it's having some emission issues. But the fact that the garage want to straight away go and replace the fairly new cat without first investigating other possible causes ie. faulty sensors / dirty filters that are cheaper fixes just makes me wonder if they're trying to rip me off.

Thanks in advance for any advice.

Gloomendoom

What caused the previous cat to fail? If it wasn't rectified, it could have caused the replacement to fail too.

forgotmyname

Replacing the Cat may solve the short term problem of passing the MOT. But as above why are they failing in the first place?

Get the car checked properly. Running rich? Using oil?

Mankysteve

Gloomendoom wrote: »

What caused the previous cat to fail? If it wasn't rectified, it could have caused the replacement to fail too.

This, there will be something up with the engine.

jimmylad007

It was replaced before as it physically broke after the mountings failed.

facade

If the replacement was a discount one, or eBay special, they don't last very long.

4743hudsonj

As above. The main catalysts in cat converters are Platinum and Rhodium both of with are exceptionally rare and ridiculously expensive. Even at one atom thick, a small cat should cost over £200 so paying less means your getting an inferior product which wont do its job properly and wont last long at all.

Id suggest getting a strong "one shot" fuel cleaner in (preferably a half tank) and driving it as much as possible for the next week before taking it for the free retest. Prior to the MOT, drive it like you've stolen it for 20 minutes and it should pass.

salubrious

I suspect with the car being the year it is, it had a cheapo cat put on it last time out i.e a none type approved part.

The readings very much look like a cat issue, so I wouldn't start throwing money around at anything other than a decent cat.

Just for your information, on the print out of the emissions result there will be either a engine temp reading or a cooling fan cut in note.

Strider590

At 0.41% it's 0.11% over the limit for that car.

What sort of driving does it experience?

It probably worth doing to the mentioned "Italian tune up", it might be enough to bring it back into spec.

There are other things which could cause this, things that should have been done at the service intervals.

AdrianC

Cheap cat dies in short order. Hold the front page.

Nodding_Donkey

I dunno, 18 months is a long time for a cheap cat. I know someone that fitted an eBay cheapo and it lasted less then two weeks.