Yaris ('00) failing NCT on emissions

fricatus

Evening all...

GF has a '00 1.0L Toyota Yaris which just failed its NCT on emissions. She didn't get it serviced beforehand (usual strategy of using first NCT to find out what was wrong before shelling out money on a service...)

Different people are saying different things, e.g. Toyota dealer reckons there's an issue with the airflow meter, whereas local mechanic says the airflow meter is OK. He's mentioned the cat as a possible issue.

I had an identical fail a few years ago with a Mitsubishi Carisma which turned out to be simply that the engine/cat hadn't yet warmed up to operating temperature - after a 20-minute spin on the motorway it passed with flying colours, so I've also got my two cents to throw in...

Any ideas? Anyone come across a similar issue? Thanks all...

Tipsy Mac

Some people say if you keep the revs high and drive the car fairly hard going to the NCT it will help clear the gank out of the system and help you pass the test.

Renegade_Archer

Ah yes, the Italian tune-up.Worth a try, although if it failed badly it might mean a knackered cat, or you're running rich, or both

Mr.Diagnostic

Are any of the opinions you mention the result of testing/diagnosis?

rccaulfield

Main dealers would know from pluggin into the ecu- or are they just guessing??

Nonoperational

I imagine it could be airflow meter, cat, lambda sensors...dealer should be able to plug it in to rule out any sensor problem.

put some Paraffin in the tank, it helps with lowering emissions for test.

itarumaa

Why dont you copy/paste the details from the NTC paper to here,

so we can see what the emissions values are.

Much easier to quess:)

JoeySully

hellboy99 wrote: »

put some Paraffin in the tank, it helps with lowering emissions for test.

Maybe for an old starlet but i wouldn't do this to newer cars! OP need to get plugged in at the dealer or post the emissions reading ! it might help.
it could be costly swapping in new parts to find out that the problem was not solved.

Vertakill

Depends how badly it failed. If it only just barely failed, I'd try drive the shíte out of it on the way to the NCT and send it through. Otherwise, as the other posters have mentioned, you'd probably be best off bringing it to a garage as it is more than likely something you're not going to be able to diagnose yourself.

Quazzie

Without seeing detailed results its impossible to give any kind of accurate diagnosis and therefore anything you read here is speculaton and hopeful guesswork

fricatus

itarumaa wrote: »

Why dont you copy/paste the details from the NTC paper to here,

so we can see what the emissions values are.

Much easier to quess:)

Quazzie2002 wrote: »

Without seeing detailed results its impossible to give any kind of accurate diagnosis and therefore anything you read here is speculaton and hopeful guesswork

Agreed... why didn't I think of that last night? :rolleyes:

HC and Lambda are fine
CO at idle should be <0.5% but it was 4.11%

I think there's also a CO value at 2,500 rpm tested? As far as I know, that was OK, i.e. below 0.3%

Thanks for all the replies so far... much appreciated.

Quazzie

To me based on them results I'd be questioning the Cat. Its obviously struggling at high revs. IMO if the Airflow metre was defective I would imagine that it would be reading wrong somewhere else (HC / Lambda). as rccaulfield stated the best option is to go to your local Toyota Dealer for a diagnostic (usually about €50 from memory) and that'll give you the most comprehensive report.

Anyone else any thoughts?

thewing

Lambda Sensor, Air Flow Meter, Cat in order of expense and likely hood....Pray it's the lambda sensor...

Quazzie

Do you think the ainflow meter defect would show them results thewing. I was always thought HC or Lambda was the result of airflow defects.

Mr.Diagnostic

There is not enough info available on an NCT fail sheet to diagnose anything.

CO of 4.11% would suggest a fault in the fueling rather than a cat. If the car was running fault free without any cat fitted the CO would not be that high.