NCT - High Emissions - failed in spectacular fashion!

Basq

(03 VW Polo)

Any thoughts on what could cause emissions of this magnitude:



What's more worrying is a brand new CAT was actually put in about maybe 6 months back.

AstraOwner

Impressive!

Was the cause of the previous CAT failing rectified?

Basq

The catalytic converter was broken at the manifold if I remember correctly..

.. so was replaced with a brand new one.

George Dalton

Another one needing a rebuild....

AstraOwner

Lambda sensor is one of the common faults. I'm not sure if it would cause those figures though. A misfire maybe?
Easiest thing you can do yourself is ensure that there are no leaks.

I'm sure someone with more experience will put you right. (Edit: like George)

Renegade Mechanic

Large carbon monoxide and hydrocarbon ppm count. It's a pity they don't test all the things. If oxygen was zero, you could at least rule out the cat. I'd recommend getting a full emissions test done (ironic, I know) at a garage.

I'd get it plugged in too, for lambda sensors check and ignition coil check.
Unless its a 3cyl polo, in which case get your cylinder compression checked too. (They suffer on burnt exhaust valves..)

Edit: Beaten to it

Basq

Cheers all.

Car has given me nothing but grief in recent years so half tempted to retire the fecking thing..

.. but just in the final stages of buying a new house, so funds are the major issue at the moment.

Stoolbend

Get a diagnostic done first. To check obvious things like coolant temp sender, lambdas and egr.

Is the engine management light working properly and is it on?

Basq

Stoolbend wrote: »

Get a diagnostic done first. To check obvious things like coolant temp sender, lambdas and egr.

Is the engine management light working properly and is it on?

Yeah, will bring it for diagnostic early next week.

Pretty sure engine management light is working, but not on.

Basq

Booked into garage for diagnostics next Wednesday morning.. will let ye know how it gets on.

kildarelad

Piston rings are gone if your getting them kind of readings

dieselbug

Basq wrote: »

Booked into garage for diagnostics next Wednesday morning.. will let ye know how it gets on.

You should also book a cylinder leakage test, might tell you more than a diagnostic test will.

cletus

Was it a spurious cat?

Basq

cletus wrote: »

Was it a spurious cat?

I can't remember to be honest with you..

.. it was pricey enough, but probably a large portion was mechanic fee's - that's all I'll say.

Tempted to go back to same mechanic that did it next week, but not sure how much good it'll do.

Renegade Mechanic

Basq wrote: »

I can't remember to be honest with you..

.. it was pricey enough, but probably a large portion was mechanic fee's - that's all I'll say.

Tempted to go back to same mechanic that did it next week, but not sure how much good it'll do.

I have a bad feeling it's not the cat. Id run the diagnosis as planned next week, tbh. Full emissions test, electronic diagnostics and compression test. Should take an hour and youll know for definite then.

Victor

Basq wrote: »

What's more worrying is a brand new CAT was actually put in about maybe 6 months back.

Did they connect it? :pac:

Ascii

Just back from NCT centre with a 2005 1.4 golf. Had to go in for the retest. It passed on low idle. On high idle it passed the Lambda and HC but failed on CO. Needed less than 0.2% but came in at 0.49%.
Put in a shot of cough syrup and ran it hard over the last three nights. Went in tonight off spec hoping they would take me which they did. Passed tonight. CO was down to .10% vol. Interesting that the HC had dropped tonight to 36ppm from 91ppm but the lambda reading went up by 2%. Overall happy to have passed.

Desolation Of Smug

Can of petrol and a match..

Basq

Actually, I've been suspecting the engine is burning oil..

.. could this be potentially to blame here I wonder!

chocksaway

Basq wrote: »

Actually, I've been suspecting the engine is burning oil..

.. could this be potentially to blame here I wonder!

Yeah most likely

9935452

Basq wrote: »

Actually, I've been suspecting the engine is burning oil..

.. could this be potentially to blame here I wonder!

There was another poster on boards that had a 1.4 bora with approx 170000 miles done burning a litre of oil every 1000 miles who had no issues with emissions at ncts so i actually would wonder how much oil you would have to burn to fail for emissions

hi5

Check for blocked breather pipes or faulty PCV valve, this can cause pressure in the crankcase forcing oil up past the rings and combusting in the cylinder.